Remote Monitoring of Fixed Structures

ABSTRACT

Arrangement and method for monitoring a structure at a fixed location, e.g., a house, parked boat or parked airplane, includes a monitoring or sensor system arranged to obtain information about the structure, an exterior of the structure and/or an interior of the structure different than the location of the structure, and a communication system coupled to the sensor system and being provided with a location of the structure. The communication system transmits the information about the structure obtained by the sensor system and the location of the structure to a remote facility. The remote facility can therefore monitor the structure, and take steps to ensure the integrity of the reservoir and the fluid therein. To enable wireless and powerless monitoring, a power source independent of a power grid extending outside of the fixed structure may be provided to supply power to the sensor system and the communications unit.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is:

1. a continuation-in-part (CIP) of U.S. patent application Ser. No.10/940,881 filed Sep. 13, 2004 which is:

-   -   A. a CIP of U.S. patent application Ser. No. 10/457,238 filed        Jun. 9, 2003, now U.S. Pat. No. 6,919,803 which claims priority        under 35 U.S.C. §119(e) of U.S. provisional patent application        Ser. No. 60/387,792 filed Jun. 11, 2002;    -   B. a CIP of U.S. patent application Ser. No. 10/931,288 filed        Aug. 31, 2004, now U.S. Pat. No. 7,164,117;

2. a CIP of U.S. patent application Ser. No. 11/278,979 filed Apr. 7,2006 which is a CIP of U.S. patent application Ser. No. 10/931,288 filedAug. 31, 2004, now U.S. Pat. No. 7,164,117;

3. a CIP of U.S. patent application Ser. No. 11/380,574 filed Apr. 27,2006 which is a CIP of U.S. patent application Ser. No. 10/931,288 filedAug. 31, 2004, now U.S. Pat. No. 7,164,117;

4. a CIP of U.S. patent application Ser. No. 11/420,497 filed May 25,2006 which is a CIP of U.S. patent application Ser. No. 10/931,288 filedAug. 31, 2004, now U.S. Pat. No. 7,164,117;

5. a CIP of U.S. patent application Ser. No. 11/619,863 filed Jan. 4,2007 which is a CIP of U.S. patent application Ser. No. 10/931,288 filedAug. 31, 2004, now U.S. Pat. No. 7,164,117;

6. a CIP of U.S. patent application Ser. No. 11/755,199 filed May 30,2007;

7. a CIP of U.S. patent application Ser. No. 11/843,932 filed Aug. 23,2007; and

8. a CIP of U.S. patent application Ser. No. 11/865,363 filed Oct. 1,2007.

All of the foregoing patent application and all references, patents andpatent applications that are referred to below are incorporated byreference in their entirety as if they had each been set forth herein infull.

FIELD OF THE INVENTION

The present invention relates to arrangements and methods for monitoringfixed structures such as buildings and vacations homes, for break-ins,fire, smoke, water, pollution, etc.

BACKGROUND OF THE INVENTION

A detailed discussion of background information is set forth in parentapplications listed above and incorporated by reference herein. All ofthe patents, patent applications, technical papers and other referencesreferenced below and in the parent applications are incorporated hereinby reference in their entirety. Various patents, patent applications,patent publications and other published documents are discussed below asbackground of the invention. No admission is made that any or all ofthese references are prior art and indeed, it is contemplated that theymay not be available as prior art when interpreting 35 U.S.C. §102 inconsideration of the claims of the present application.

Definitions in the Background of the Invention section of any of theabove-mentioned applications are also generally, but not restrictively,applicable herein.

OBJECTS AND SUMMARY OF THE INVENTION

It is an object of the present invention to provide new and improvedsystems for obtaining information about fixed structures for thepurposes of, for example, determining whether there is an unauthorizedperson or persons in the structure or condition which can lead to or hascaused damage to the structure, and transmitting that information to oneor more remote facilities.

In order to achieve this object and possibly others, an arrangement formonitoring a structure at a fixed location in accordance with theinvention includes a monitoring or sensor system arranged to obtaininformation about the structure or an interior of the structuredifferent than the location of the structure, and a communication systemcoupled to the sensor system and being provided with a location of thestructure. The communication system transmits the information about thestructure obtained by the sensor system and the location of thestructure to a remote facility. Various sensors are envisioned includingan electromagnetic sensor, camera, ultrasound sensor, capacitive sensor,chemical sensor, moisture sensor, radiation sensor, biological sensor,temperature sensor, pressure sensor, radiation sensor, an intrudersensor, a fire detector, a smoke detector, a water detector and apollution sensor.

The sensor system may be arranged to periodically obtain informationabout the structure and provide the information to the communicationssystems which transmits the information to the remote facility. Toenable wireless and powerless monitoring, a power source independent ofa power grid extending outside of the fixed structure may be provided tosupply power to the sensor system and the communications unit.

To efficiently manage power yet provide suitable protection, the sensorsystem may include an initiation device for periodically initiating thesensor system to obtain information about the fixed structure. A wakeupsensor system detects the occurrence of an internal or external event,or the absence of an event for a time period, requiring a change in thefrequency of monitoring of the fixed structure. The initiation device iscoupled to the wakeup sensor system and changes the rate at which itinitiates the sensor system to obtain information about the fixedstructure in response to the detected occurrence of an internal orexternal event by the wakeup sensor system.

The sensor system may be controllable by the remote facility to obtaininformation about the fixed structure. The sensor system may include anintegral energy providing system and is wirelessly connected to theprocessor.

A method for monitoring a fixed structure in accordance with theinvention includes arranging a sensor system to obtain information aboutthe fixed structure different than the location of the body of fluid,obtaining information about the fixed structure via the sensor system,and transmitting the obtained information about the fixed structure andthe location of the fixed structure to a remote facility. Thecommunication system may be wirelessly coupled to the sensor system. Anenvironment around the fixed structure may be monitored by the sensorsto obtain information about the environment around the fixed structure,and the information about the environment around the fixed structuretransmitted to the remote facility along with the information about thefixed structure and the location of the fixed structure. The sensorsystem may be controlled to periodically obtain information about thefixed structure. At least one reactive system may be arranged at thefixed structure to adjust a condition in the fixed structure andcontrolled by the remote facility based on the transmitted informationabout the fixed structure obtained by the sensor system.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings are illustrative of embodiments of the systemdeveloped or adapted using the teachings of at least one of theinventions disclosed herein and are not meant to limit the scope of theinvention as encompassed by the claims.

FIG. 1 illustrates a first embodiment of a cargo space equipped with asystem in accordance with the invention for obtaining information from atagged object in the cargo space.

FIG. 2 illustrates a second embodiment of a cargo space equipped with asystem in accordance with the invention for obtaining information from atagged object in the cargo space.

FIG. 3 illustrates an embodiment of a cargo space with RF windows.

FIG. 4 illustrates an embodiment of a cargo space with an antennamultiplexer arrangement.

FIG. 5 illustrates an embodiment of a cargo space with multiple antennaswhich enable the position of a tag to be determined based on receptionof signals by the antennas.

FIGS. 6 and 7 are block diagrams of an interrogator with a singleantenna which may be used in the invention.

FIG. 8 is a block diagram of an interrogator with multiple antennaswhich may be used in the invention.

FIG. 9 illustrates systems for deriving or harvesting electrical powerfor use in the invention.

FIG. 10 illustrates a method of using triangulation to determine thelocation of a tag within a cargo space in accordance with the invention.

FIG. 11 is a cutaway view of a vehicle showing possible mountinglocations for vehicle interior temperature, humidity, carbon dioxide,carbon monoxide, alcohol or other chemical or physical propertymeasuring sensors.

FIG. 12 is a schematic of a vehicle with several accelerometers and/orgyroscopes at preferred locations in the vehicle.

FIG. 13 illustrates a driver with a timed RFID standing with groceriesby a closed trunk.

FIG. 14 illustrates the driver with the timed RFID 5 seconds after thetrunk has been opened.

FIG. 15 illustrates a trunk opening arrangement for a vehicle inaccordance with the invention.

FIG. 16A is a view of a SAW switch sensor for mounting on or within asurface such as a vehicle armrest.

FIG. 16B is a perspective view of the device of FIG. 16A with theforce-transmitting member rendered transparent.

FIG. 16C is a perspective view of an alternate SAW device for use inFIGS. 16A and 16B showing the use of one of two possible switches, onethat activates the SAW and the other that suppresses the SAW.

FIG. 16D is a schematic of a RFID controlled by a switch.

FIG. 16E is a schematic of a SAW device controlled by a switch.

FIG. 16F is a schematic of a backscatter antenna which is controlled bya switch.

FIG. 16G is a schematic of circuit for a monitoring system in accordancewith the invention which has two switches.

FIG. 16H illustrates one embodiment of a switch whereby activation ofthe switch provides the energy necessary to power an RFID.

FIG. 17 is a top view of a system for obtaining information about avehicle or a component therein, specifically information about thetires, such as pressure and/or temperature thereof.

FIG. 18 is a side view of the vehicle shown in FIG. 17.

FIG. 19 is a schematic of the system shown in FIGS. 17 and 18.

FIG. 20 is a top view of an alternate system for obtaining informationabout the tires of a vehicle.

FIG. 21 is a perspective view showing a shipping container including oneembodiment of the monitoring system in accordance with the presentinvention.

FIG. 22 is a flow chart showing one manner in which a container ismonitored in accordance with the invention.

FIG. 23A is a cross-sectional view of a container showing the use ofRFID technology in a monitoring system and method in accordance with theinvention.

FIG. 23B is a cross-sectional view of a container showing the use ofbarcode technology in a monitoring system and method in accordance withthe invention.

FIG. 23C is a cross-sectional view of a refrigerated container showingthe use of a diagnostic module in a monitoring system and method inaccordance with the invention.

FIG. 24 is a flow chart showing one manner in which multiple assets aremonitored in accordance with the invention.

FIG. 25 is a schematic side view of a movable storage tank, commonlyknown as a Frac tank, containing a level monitoring system in accordancewith the invention.

FIG. 26 is a perspective view of an oil or chemical storage tankcontaining a level monitoring system in accordance with the invention.

FIG. 27 shows one preferred method of determining the level of a fluidin a tank that is independent on temperature or the speed of sound.

FIG. 28 is a schematic illustration of the method of FIG. 27.

FIG. 29 is a cross-sectional view of an embodiment of a fluid levelmeasuring system in accordance with the invention.

FIG. 30 is an enlarged view of the fluid level measuring system shown inFIG. 29.

FIG. 31 is a view of a Doppler ultrasonic flowmeter.

FIG. 32 is a view of a transit time ultrasonic flowmeter.

FIG. 33 is a view of a turbine flowmeter.

FIG. 34 is a view of a target flowmeter.

FIG. 35 is a section of a pipeline illustrating two bi-directionalultrasonic transit time flowmeters displaced in the pipeline, twoacoustic receivers in each flowmeter for monitoring the pipe forabnormal sounds or vibrations indicative of an attempt to breech thepipe, an energy harvesting system for generating needed energy forprolonged operation and appropriate electronic circuitry.

FIG. 36 is an enlarged view of the power generator, flow sensor andvibration sensor assembly of FIG. 35.

FIGS. 37A and 37B illustrate the flow of information from variousmonitoring stations along a pipeline to a secure location where thecumulative information can be transmitted to the home station.

FIG. 38 is a schematic showing a reservoir monitored in accordance withthe invention.

FIG. 39 is a schematic showing a house monitored in accordance with theinvention.

DETAILED DESCRIPTION OF THE INVENTION

Although many of the examples below relate to a cargo space in an asset,the invention is not limited to any particular space in any particularasset and is thus applicable to all types of assets including vehicles,shipping containers, fixed or movable storage tanks, pipelines and trucktrailers and to all spaces or compartments of a vehicle including, forexample, the passenger compartment and the trunk of an automobile ortruck. For the purposes of this disclosure the word vehicle will be usedto represent all such containers, pipelines, trucks, trains, boats,airplanes and other vehicles where appropriate.

Prior to describing the invention in detail, definitions of certainwords or phrases used throughout this patent document will be defined:the terms “include” and “comprise”, as well as derivatives thereof, meaninclusion without limitation; the term “or” is inclusive, meaningand/or; the phrases “associated with” and “associated therewith”, aswell as derivatives thereof, may mean to include, be included within,interconnect with, contain, be contained within, connect to or with,couple to or with, be communicable with, cooperate with, interleave,juxtapose, be proximate to, be bound to or with, have, have a propertyof, or the like; and the term “controller”, “control module”, “controlunit”, “processor” are generally synonymous and mean any device, systemor part thereof that controls at least one operation, whether such adevice is implemented in hardware, firmware, software or somecombination of at least two of the same. It should be noted that thefunctionality associated with any particular controller may becentralized or distributed, whether locally or remotely. Definitions forcertain words and phrases are provided throughout this patent document,and those of ordinary skill in the art will understand that suchdefinitions apply in many, if not most, instances to prior as well asfuture uses of such defined words and phrases.

Referring to the accompanying drawings, FIGS. 1-10 illustrate a methodand system for identifying and locating an RFID-tagged article inside acargo space defined by a frame. The RFID tags can be active, passive ora combination of both, or MIR or Wibree transmitters, or devicesproviding backscatter including antennas and dihedral and corner cubereflectors. The system can employ multiple antennas inside or outside ofa cargo space, truck trailer or other vehicle cargo space as illustratedin FIGS. 1-6. The system is preferably designed for a low power batteryoperation when the cargo space is not tethered to a power source. Someenergy harvesting methods for powering the system are shown in FIGS. 9and 36. The system requires little power and has a low duty cycle whennot connected to a power source. Thus the system will provide RFID tagidentification, and in some cases sensor monitoring information, formany years with internal battery power.

A passive RFID tag can operate at about 915 MHz (ISM band) complyingwith FCC rule 15, for example, or other rules that may apply either inthe US or other countries. The frequency can be any frequency permittedunder these rules.

FIG. 1 illustrates an embodiment of a cargo space with three antennas10, 12, 14 spaced in a triangular fashion and connected to aninterrogator 16 internal to the cargo space with the antennas 10, 12,and 14 shown in one possible configuration arranged on a common wall ofthe cargo space. The interrogator 16 can be arranged inside or outsideof the cargo space and can be mounted on the outside, within or on theinside of a wall defining the cargo space. For example, for the shippingcontainer shown in FIG. 1 having four walls, a roof and a floor, theantennas 10, 12, 14 can be arranged in or on the inside or outside ofthe front wall. This wall may be the fixed wall opposite the door of theshipping container. In other embodiments, the antennas 10, 12, 14 can bearranged in or on the other walls of the container.

The interrogator 16 may be arranged within the triangle defined by theantennas 10, 12, 14, for example, at or about the approximate center ofthe triangle. In other embodiments with multiple antennas, theinterrogator may be situated to be equidistant from all of the antennas.Nevertheless, the location of the interrogator relative to the antennasis not critical to the practice of the invention and the interrogatormay be placed anywhere on the asset defining the cargo space, or evenseparate and apart from the asset, as described below. The interrogator16 may be connected to the antennas 10, 12, 14 using wires orwirelessly. The time delay for the signals to travel from theinterrogator 16 to the antennas 10, 12, 14 needs to be considered in thecalculations to determine the distance to an RFID tag. Thesecalculations are simplified if the distance to each antenna 10, 12, 14from the interrogator 16 is the same.

The interrogator 16 can be connected to a satellite communication unitor other communication unit 18 from its location associated with thecargo space, e.g., outside or in the interior of the cargo space, usinga wire or wirelessly using an antenna. As shown, communication unit 18can be arranged on an exterior surface such as a roof of the asset. Thesatellite or other communication unit 18 can have an external antennaand can be used to send tag and other information to a remote site. Thedistances from each antenna 10, 12, 14 to an RFID device or tag 20 areshown as D1, D2 and D3. These distances can be determined by a processorwithin the interrogator 16 shown schematically in FIG. 8, or theinformation obtained by the interrogator 16 can be transmitted toanother processor that may be on the frame defining the cargo space orat a remote location where the calculations can be performed. Theinterrogator 16 can additionally obtain information from sensors mountedin conjunction with and connected to tag 20 in addition to the tagidentification. These sensors can, for example, monitor the motion,temperature, integrity, attitude, pressure, weight, leakage and/or anyother parameter associated with the object with which the tag isassociated or its environment.

In the above example, the interrogator 16 transmits an interrogationsignal and the tags, such as tag 20, return a response with the desiredinformation. An alternate approach is for the tag 20, for example, toperiodically transmit a signal which is received by antennas 10, 12, and14. If a clock in the tag 20 has been synchronized with a clock in theinterrogator 16, then the distances D1, D2, and D3 can be determinedprovided multipath and other effects are ignored or otherwise dealtwith. If a fourth antenna 8 is provided, then four signals are receivedby the interrogator 16 and clock synchronization is unnecessary. Addingadditional antennas can improve the location determination of tag 20especially when the transmission path to the tag 20 is obstructedleading to signal transmission delays and multipath complications Thus,in this embodiment, the RFID device 20 returns a signal at a specifictime after receipt of an interrogation signal or pulse from one or moreof the antennas 10, 12, 14, or at an appointed or predesignated time.

In one embodiment when the interrogator 16 causes transmission ofsignals from multiple antennas 10, 12, 14, the RFID 20 when receivingsignals from one or more of these antennas 10, 12, 14 may be arranged orprogrammed to provide information in the return signal indicative of aphase or relative time of reception of signals from the multipleantennas. A processor such as the one associated with the interrogator16 could then analyze the return signals and, from the phase or timereception information, derive information about the location of the RFIDdevice 20 or object to which it is mounted.

FIG. 2 illustrates an embodiment of a cargo space with three antennas22, 24, 26 spaced in a triangular fashion located on the roof, ceilingor top of the shipping container defining the cargo space and connectedto an interrogator 28 internal to the cargo space. The interrogator 28is connected to an external antenna 30 and can also be connected to asatellite or other communication unit as in FIG. 1. The distances fromeach antenna 22, 24, 26 to the RFID device or tag 32 are shown as D1, D2and D3. The interrogator 28 may be arranged within the triangle definedby the antennas 22, 24, 26 or elsewhere. The variations described forthe embodiment shown in FIG. 1 are equally applicable to thisembodiment.

Mounting of the antennas 22, 24, 26, or possibly any other type ofelectromagnetic energy transmitter, on the roof of the shippingcontainer is advantageous in that is it very unlikely to interfere withthe maximum use of the cargo space provided by the shipping container.

FIG. 3 illustrates an embodiment of a shipping container defining acargo space with multiple RF windows 34, 36, 38, 40 in the frame of thecontainer. The windows 34, 36, 38, 40 allow for the signal to and fromone or more RFID devices or tags 42 in the cargo space to transmit andreceive signals from an interrogator 44 such as shown schematically inFIG. 6 which can be located outside of the cargo space. This embodimenttherefore enables an interrogator 44 to obtain signals via antenna 46from an RFID device or tag 42 within a cargo space while theinterrogator 44 is separate and apart from the cargo space. Such RFwindows would be needed anytime metal walls are interposed between theinterrogator and its antenna, and the space defined by the frame. It isthus conceivable that the interrogator and its antenna may even bearranged on the frame yet require one or more RF windows to enablesignals from the antenna to pass into the space and return signals fromany RFID devices in the space to pass out of the space to be received bythe antenna. Walls made from other materials may also pose transmissionproblems depending on the interrogator frequency. Thus, knowledge of thematerials of the walls is a factor when determining the interrogatorfrequency.

The size, location and number of RF windows in an asset, such as theshipping container defining the cargo space shown in FIG. 3, can varydepending on, for example, the expected and possible locations of RFIDdevices or tags in the cargo space or other space defined by the asset,the dimensions of the cargo space or other space defined by the asset,and the expected relative position between the antenna of theinterrogator and the RFID devices. It is possible that one or more RFwindows be situated at the same location on a particular type ofshipping container and that a scanning system being provided for usewith such shipping containers which is designed to accept one or moreshipping containers in a position in which the RF windows areautomatically properly aligned with an antenna of an interrogator of thescanning system. This will simplify the scanning of the shippingcontainers.

FIG. 4 illustrates an embodiment of a cargo space with a multiple ofinternal antennas 46, 48, 50, 52 connected to an antenna multiplexer 54(such as a PE4261 SP4T RF UltraCMOS™ Flip Chip Switch manufactured byPeregrine Semiconductor). As shown, antennas 46, 48, 50, 52 are allarranged at the top of the shipping container defining the cargo space.

The multiplexer 54 may be connected to an antenna 56 outside of thecargo space (an external antenna, yet one which is still mounted on orattached to the frame defining the cargo space) for communications withan external interrogator such as illustrated in FIG. 6. A transceivermay be connected between the multiplexer 54 and the external antenna 56in order to increase the signal strength of the signals from the RFIDdevice 58 which is internal to the shipping container defining the cargospace. The external antenna 56 is used to communicate with aninterrogator and its antenna which is used to control the transmissionsof signals by the antennas 46, 48, 50, 52 and process signals receivedby the antennas into information about the RFID device 58 or an objecton or to which the RFID device is attached. A processor may be used forthis purpose and may either be part of the interrogator or separatetherefrom which can be remote from the interrogator.

The RFID device location in the cargo space may be determined bymeasuring the distances from the RFID device 58 to each of the internalantennas 46, 48, 50, 52 by triangulation as illustrated in FIG. 10 anddescribed below. Triangulation may be used in the same manner wheneverthere are at least three antennas which receive signals generated by thepresence of an RFID device in a monitored cargo space. If at least fourantennas are used, then the internal time delay in the RFID circuitryneed not be known. This is similar to the techniques used fordetermining the location of a GPS receiver based on receptions from foursatellites. Whenever GPS is mentioned herein, it is understood that itencompasses Glonass, Galileo, Compus or other similar satellite-basedpositioning systems.

FIG. 5 illustrates an embodiment of a cargo space with multiple internalantennas 60, 62, 64, 66, 68, 70 connected to an antenna multiplexer 72(such as the PE4261). The multiplexer 72 may be connected to an externalantenna 74 outside of the cargo space for communications with anexternal interrogator such as illustrated in FIG. 6. As in theembodiment of FIG. 4, a transceiver may be connected between themultiplexer 72 and the outside antenna 74 for increasing the signalstrength of the signals from the RFID device 76 or RFID devices whichare within the cargo space. The RFID device location in the cargo spacemay be determined by measuring the signal strengths from the internalantennas 60, 62, 64, 66, 68, 70, whereby the antenna closest to the RFIDdevice 76 will have the largest or strongest signal therefore the zonewhere the RFID device 76 is located in the cargo space may bedetermined.

When using multiple antennas on an asset and deriving the generallocation of the RFID device or RFID-device equipped object based on thesignal strength, the antennas can be distributed or spaced apart alongany single dimension of the asset, e.g., longitudinally for the shippingcontainer as shown in FIG. 5. In this manner, the approximatelongitudinal location of the RFID device or object equipped therewithcould be determined. Of course, when two antennas provide signals havingequal strength, it could be derived that the RFID device is situatedapproximately half-way between the antenna locations.

In one embodiment, the antennas are arranged along a longitudinal centerline of the cargo space, e.g., down the center or side of a shippingtrailer or container.

FIG. 6 illustrates a block diagram of an interrogator with a singleantenna which may be used in the embodiments herein. Information fromthis interrogator may be displayed locally or sent over a communicationslink, such as a satellite, cell phone, internet or equivalent link, to aremote location for processing, logging, re-transmission or for anyother purpose.

The interrogator 78 includes a pair of oscillators 80, 82, a modulator84 processing the output from oscillators 80, 82 and providing output toa power amplifier 86, and a circulator 88 connected to the poweramplifier 86 and providing a signal for transmission by the antenna 90with a signal being received by antenna 90 being directed through thecirculator 88 to an amplifier 92. A phase detector 94 is connected tothe oscillator 82, modulator 84 and amplifier 92 which performs a phasecomparison between the signals transmitted and received via antenna 90.A microprocessor 96 is coupled to the modulator 84 and phase detector 94which analyzes the phase comparison to determine information about aRFID device which returns a signal to the antenna 90. This informationmay be distance or range information, which may be provided to anexternal device or a display. Additionally or alternatively, it may beidentification information, or information from any RFID deviceassociated sensors.

The information may be derived using the known speed of the waves (speedof light) and the time for travel of the waves, since the distancebetween the antenna and the RFID-device is equal to one-half the speedmultiplied by the total travel time.

FIG. 7 illustrates a block diagram of an interrogator with a singleantenna similar to that shown in FIG. 6. Information from thisinterrogator may be displayed locally or sent over a communications linkvia a communications device 97 to a remote location as above. Thisembodiment of an interrogator shows a method for measuring the distancefrom the interrogator antenna to the antenna of an RFID device. Themodulation used may be either amplitude or frequency; the phase detectormay be of the phase/frequency type. An exemplifying calculation foramplitude modulation would involve determining the time for travel ofthe waves, which is equal to twice the distance between the antenna andthe RFID-device (having a set maximum, for example, of 5 meters) dividedby the speed of light.

FIG. 8 illustrates a block diagram of an interrogator with multipleantennas which may be used in embodiments herein. The block diagram issimilar to that shown in FIG. 6 and the same reference numeralsdesignate the same elements. However, in this embodiment, individualantennas are selected by a MUX 98 (which may be one designated in theliterature as a PE4261). The MUX 98 controls the transmission andreception of signals via antennas 100, 102, 104. Any number of antennasmay be provided. The PE4261 is limited to six antennas. Control of theMUX 98 may be achieved using the microprocessor 96 which is coupledthereto.

Information from this interrogator may be displayed locally or sent overa communications link to a remote location as described above. Thisembodiment of an interrogator shows a method for measuring the distancefrom the selected interrogator antenna to a tag antenna. The modulationmay be amplitude, frequency or pulse; the phase detector may be of thephase/frequency type. Example calculations are shown for amplitudemodulation. By using the distances from the antennas 100, 102, 104 to atag, the location of the tag can be calculated by triangulation as shownin FIG. 10 and described below.

FIG. 9 illustrates three exemplary methods for deriving or harvestingelectrical power for the operation of interrogators, multiplexers,transceivers or transmitters, as well as any other electricity consumingdevices on the cargo container needed for the operation or for thepurpose of gathering information about a tagged object in the cargospace. Such devices can be situated within the cargo space or in or onthe structure defining the cargo space. These energy harvesting devicesinclude solar panels 106 (shown in the top of the cargo container), avibration power generator 108 (shown on a side of the container) and amagnetic field variation device 110 which generates electrical powerbased on variations in a magnetic field caused by movement of thecontainer. Other energy harvesting devices can also be used.

FIG. 10 illustrates a method of using triangulation to determine thelocation of a typical tag 112 within a cargo space, which may be used inembodiments described herein. The exemplary tag location determinationby triangulation is shown for two dimensions in the x, y plane but maybe readily extended to a three-dimensional x, y, z space.

Let:

R1=The measured range from Antenna 114 to the tag 112.

R2=The measured range from Antenna 116(a,0) to the tag 112.

a=known distance between antennas

R1² :=x ² +y ²

y ² :=R1² −x ²  Eq (1)

R2²:=(x+a)² +y ²  Eq (2)

substituting:

R2²:=(x+a)² +R1² −x ²

R2² −R1² :=x ²+2a·x+a ² −x ²

2·a·x:=R2² −R1² −a ²

R1 and R2 are measured values and a is known by the distance between theantennas 114, 116 therefore; x can be computed. Once x is computed y canbe found by substituting x into equation 1.

$x:=\frac{\left( {{R\; 2^{2}} - {R\; 1^{2}} - a^{2}} \right)}{2 \cdot a}$

The location of the tag 112 in three dimensions can now be easily foundby those skilled in the art.

The above analysis has been based on the time of arrival of a signalfrom a tag at the various antennas relative to the time of transmissionand the known delay in the RFID tag between reception of theinterrogation signal and transmission of the return signal by the tag. Aset of equations can also be derived based on four antennas thatprovides the three dimensional location of the tag plus the time thatthe transmission was sent from the tag based on the time of arrival atthe four antennas. Other methods based on the angle of arrival canpermit vectors to be drawn that pass through the tag location and thenbased on the calculation of the intersection of these vectors, thelocation of the tag can be found. Information about this technique isdisclosed, for example, in Z. Wen, L. Li, and P. Wei “Fast DirectionUsing Modified Pseudocovariance Matrix”, IEEE Transactions on Antennasand Propagation, Vol 54, No. 12, December 2006, and articles referencedtherein.

An alternate approach is for the antennas to send short pulses which allof the tags would hear and record the times of arrival. The recordedarrival times would then be sent back to the interrogator from which theinterrogator processor could determine the location of a tag based onthe pattern of signals that the tag heard. Each antenna could append anID so that the tag could record the tag signal correspondence. Thesetechniques can be based on relative times or on absolute time. Thelatter could be determined by a variety of methods including syncing theclock on each tag with the interrogator clock or, alternately, recordingthe time of arrival from at least four antennas.

Another method of determining the location of a tag is to enable the tagto either receive or transmit ultrasound. In the latter case, the tagwould emit an ultrasonic pulse when it receives an RF pulse andlisteners distributed around the cargo space would receive eachultrasonic pulse at a different time and thereby know, or enable adetermination of, the distance to the tag. If there are three listenersand the time that the interrogation pulse was sent is known, then thetag location is known based on the known location of the listeners sincethe speed of sound is much slower than the speed of light.

The methods and systems described above for interacting with RFIDdevices or tags are equally applicable for other types of tags orresponsive devices including but not limited to various SAW devices,resonators and reflectors (e.g., corner cube or dihedral reflectors),such as disclosed in the applications listed above. The informationobtained by the methods and system in accordance with the inventionwhich interact with these devices may be identification information andpositional information. In the latter case, when tags are installed ontocomponents of assets, such as a seat or door in a vehicle, theirpresence, positions and/or orientations can be determined and used tocontrol other systems. Such systems include vehicular systems having anoutput which varies as a function of the presence, position and/ororientation of the components (which may correlate to the presence,position and/or orientation of human occupants of the vehicles).

The methods and system in accordance with the invention can be used tointerrogate multiple RFID devices or similar tags. In this case, theidentification, location and/or motion of multiple RFID devices orobjects associated therewith can be determined.

In a preferred embodiment, the asset is a vehicle and one or morecomponents are equipped with RFID devices. The interrogator controlstransmission of RF signals from the antennas to cause these RFID devicesto generate return signals. Analysis of these return signals by aprocessor associated with the interrogator can be used to deriveinformation about the components. In this regard, reference is made tothe disclosure of U.S. Pat. No. 6,820,897 which is directed to, amongother things, the use of resonators arranged on vehicular components.

Additional variations of any of the embodiments of the methods andsystems described above include the ability of the interrogator orantenna multiplexer to transmit signals from the RFID devices orinformation derived from the RFID devices and any sensors associatedtherewith to one or more locations or sites remote from the assetcontaining the RFID device. This allows remote monitoring of assets andthe contents of such assets.

The presence of an interrogator on the same frame or structure whichdefines a space into which RFID devices or objects equipped with RFIDdevices reside greatly simplifies the ability to scan spaces of theseframes or structures. The objects equipped with the RFID devices mayinclude sensors. In addition, such sensors may be arranged to beindependently interrogated by the interrogator which would thusinterrogate the RFID devices and the sensors. These sensors may betemperature, optical, flow, humidity, chemical, biochemical, current,voltage, magnetic field, electric field, force, acceleration, velocity,displacement, position, vibration, acoustic, ultrasonic, radiation,charge, viscosity, density, electrical resistance, electrical impedance,electrical capacitance, electrical inductance, optical, opacity,turbidity and pressure sensors.

The presence and identification of people can be derived using RFIDdevices, via analysis of information from RFID devices mounted to thevehicle's structure such as seats, and then transmitted off of thevehicle. This concept is disclosed in U.S. Pat. No. 5,829,782, alongwith the presence of tags and tag monitors inside a vehicle.

The methods and systems described above can also be used to determinethe location of RFID devices exterior and proximate to a cargo space, onor in another part of the vehicle containing the interrogator.

The power transmitted by the antennas may be higher in view of thetransmission of the radio frequency signals into a closed cargo space.In this regard, transmission rules by the FCC may not apply within anenclosed volume with regard to frequencies or power.

The invention is also applicable to the placement of RFID device onluggage or baggage which is placed on airplanes. In this case, apassenger and others can always locate their baggage, provided they havean interrogator to determine the location of each passenger's luggage.This permits airline personnel to locate particular baggage within aplane for removal, for example, if the owning passenger is not on board.The system can thus detect and locate luggage and baggage, or otherobjects, after it is in a vehicle equipped with an interrogator.

Another feature of some embodiments of the invention is the use of smartantennas and a single interrogator or reader for use in determining thelocation of an RFID device or object equipped therewith. The method andsystem can be designed and configured to use minimal energy to achievethis location-determination.

The RFID devices in any of the embodiments herein may utilize an RFIDswitch, or other technique, to limit transmissions.

Devices similar to RFID devices can be designed to transmit MIR pulsesfor location purposes. Such pulses can be coded to provide sensor and IDinformation. Such a system can provide for a longer range transmissionand, due to the multiple frequencies involved, can provide for greaterpenetration through surrounding objects that might otherwise block anormal RFID signal. Such an MIR-based system can also operate at verylow energy levels yielding many years of operation between batterycharging or battery changing.

In one embodiment, transmission via the antennas is based on thelocation of the antennas. Thus, the interrogator can control theantennas to transmit as a function of the location which is known to theinterrogator, or the processor which controls the interrogator. This canbe used to minimize signal overlap or collisions.

For an RFID or other device which can transmit or generate a returnsignal at two or more frequencies, it is conceivable that the distanceto the RFID device from the antenna can be determined by determining thephase between the received signals at the different frequencies.

Since the best position to place antennas on a shipping container orframe of another asset including an interior, object-receiving space, isnot always known in advance, a process can be implemented to find thebest location for the antennas. This process may entail arranging alarge number of antennas on the asset and conducting tests todetermining the position of RFID devices in the space. Antennas areremoved in stages and more tests conducted until the optimum number andposition of antennas for the space which provides an acceptable accuracyis determined.

RFID devices can be used in combination with SAW devices and otherwireless sensors. Many sensors are now in vehicles and many more will beinstalled. The following disclosure is primarily concerned with wirelesssensors which can be based on MEMS, SAW and/or RFID technologies. Suchvehicle sensors include tire pressure, temperature and accelerationmonitoring sensors; weight or load measuring sensors; switches; vehicletemperature, acceleration, angular position, angular rate, angularacceleration sensors; proximity; rollover; occupant presence; humidity;presence of fluids or gases; strain; road condition and friction,chemical sensors and other similar sensors providing information to avehicle system, vehicle operator or external site. The sensors canprovide information about the vehicle and/or its interior or exteriorenvironment, about individual components, systems, vehicle occupants,subsystems, and/or about the roadway, ambient atmosphere, travelconditions and external objects.

For wireless sensors, one or more interrogators can be used each havingone or more antennas that transmit energy at radio frequency, or otherelectromagnetic frequencies, to the sensors and receive modulatedfrequency signals from the sensors containing sensor and/oridentification information. One interrogator can be used for sensingmultiple switches, sensors or other devices. For example, aninterrogator may transmit a chirp form of energy at 905 MHz to 925 MHz,or alternately a series of one or more discrete frequencies, to avariety of sensors located within and/or in the vicinity of the vehicle.These sensors may be of the RFID electronic type and/or of the surfaceacoustic wave (SAW) type or a combination thereof. In the electronictype, information can be returned immediately to the interrogator in theform of a modulated backscatter RF signal. In the case of SAW devices,the information can be returned after a delay. RFID tags may alsoexhibit a delay due to the charging of the energy storage device. Onesensor can respond in both the electronic (either RFID or backscatter)and SAW-delayed modes.

When multiple sensors are interrogated using the same technology, thereturned signals from the various sensors can be time, code, space orfrequency multiplexed. For example, for the case of the SAW technology,each sensor can be provided with a different delay or a different code.Alternately, each sensor can be designed to respond only to a singlefrequency or several frequencies. The radio frequency can be amplitude,code, pulse or frequency modulated. Space multiplexing can be achievedthrough the use of two or more antennas and correlating the receivedsignals to isolate signals based on direction.

In many cases, the sensors will respond with an identification signalfollowed by or preceded by information relating to the sensed value,state and/or property. In the case of a SAW-based or RFID-based switch,for example, the returned signal may indicate that the switch is eitheron or off or, in some cases, an intermediate state can be providedsignifying that a light should be dimmed, rather than or on or off, forexample. Alternately or additionally, an RFID based switch can beassociated with a sensor and turned on or off based on an identificationcode or a frequency sent from the interrogator permitting a particularsensor or class of sensors to be selected.

SAW devices have been used for sensing many parameters including devicesfor chemical and biological sensing and materials characterization inboth the gas and liquid phase. They also are used for measuringpressure, strain, temperature, acceleration, angular rate and otherphysical states of the environment. Wireless sensors can also compriseMEMS devices that are capable of chemical or biological sensing, forexample. One such device includes an array of beams etched into a chipwith the beams coated with a variety of reactants that absorb variouschemical or biological species. Typically, each beam has a differentcoating. The mass absorbed by the reactants varies the natural frequencyof a beam which can then be sensed periodically when the beams on theMEMS device are excited electrically. The pattern of frequency changesallows the determination of the presence and/or concentration of thechemical or biological species. Such a device has been used, forexample, to determine the make-up a perfumes. Such a device hasapplicability to monitoring of vehicles, and specifically compartmentsor interior spaces therein, to determine the presence of variouschemical or biological species and thus warn authorities that a shippingcontainer contains such species, for example. Within an automobile, sucha device can be used to test for carbon monoxide or alcohol vapors inthe cabin air, for example. Such a device can communicate with acontroller either by wires or wirelessly.

Economies are achieved by using a single interrogator or even a smallnumber of interrogators to interrogate many types of devices. Forexample, a single interrogator may monitor tire pressure andtemperature, the weight of an occupying item of the seat, the positionof the seat and seatback, as well as a variety of switches controllingwindows, door locks, seat position, etc. in a vehicle. Such aninterrogator may use one or multiple antennas and when multiple antennasare used, may switch between the antennas depending on what is beingmonitored.

Similarly, the same or a different interrogator can be used to monitorvarious components of the vehicle's safety system including occupantposition sensors, vehicle acceleration sensors, vehicle angularposition, velocity and acceleration sensors, related to both frontal,side or rear impacts as well as rollover conditions. The interrogatorcould also be used in conjunction with other detection devices such asweight sensors, temperature sensors, accelerometers which are associatedwith various systems in the vehicle to enable such systems to becontrolled or affected based on the measured state.

Some specific examples of the use of interrogators and responsivedevices will now be described.

The antennas used for interrogating the vehicle tire pressuretransducers can be located outside of the vehicle passenger compartment.For many other transducers to be sensed the antennas can be located atvarious positions within passenger compartment. At least one inventionherein contemplates, therefore, a series of different antenna systems,which can be electronically switched by the interrogator circuitry.Alternately, in some cases, all of the antennas can be left connectedand total transmitted power increased.

There are several applications for weight or load measuring devices in avehicle including the vehicle suspension system and seat weight sensorsfor use with automobile safety systems. As described in U.S. Pat. Nos.4,096,740, 4,623,813, 5,585,571, 5,663,531, 5,821,425 and 5,910,647 andInternational Publication No. WO 00/65320(A1), SAW devices areappropriate candidates for such weight measurement systems, although insome cases RFID systems can also be used with an associated sensor suchas a strain gage. In this case, the surface acoustic wave on the lithiumniobate, or other piezoelectric material, is modified in delay time,resonant frequency, amplitude and/or phase based on strain of the memberupon which the SAW device is mounted. For example, the conventional boltthat is typically used to connect the passenger seat to the seatadjustment slide mechanism can be replaced with a stud which is threadedon both ends. A SAW or other strain device can be mounted to the centerunthreaded section of the stud and the stud can be attached to both theseat and the slide mechanism using appropriate threaded nuts. Based onthe particular geometry of the SAW device used, the stud can result inas little as a 3 mm upward displacement of the seat compared to a normalbolt mounting system. No wires are required to attach the SAW device tothe stud other than for an antenna.

In use, the interrogator transmits a radio frequency pulse at, forexample, 925 MHz that excites antenna on the SAW strain measuringsystem. After a delay caused by the time required for the wave to travelthe length of the SAW device, a modified wave is re-transmitted to theinterrogator providing an indication of the strain of the stud with theweight of an object occupying the seat corresponding to the strain. Fora seat that is normally bolted to the slide mechanism with four bolts,at least four SAW strain sensors can be used. Since the individual SAWdevices are very small, multiple devices can be placed on a stud toprovide multiple redundant measurements, or permit bending and twistingstrains to be determined, and/or to permit the stud to be arbitrarilylocated with at least one SAW device always within direct view of theinterrogator antenna. In some cases, the bolt or stud will be made onnon-conductive material to limit the blockage of the RF signal. In othercases, it will be insulated from the slide (mechanism) and used as anantenna.

If two longitudinally spaced apart antennas are used to receive the SAWor RFID transmissions from the seat weight sensors, one antenna in frontof the seat and the other behind the seat, then the position of the seatcan be determined eliminating the need for current seat positionsensors. A similar system can be used for other seat and seatbackposition measurements.

For strain gage weight sensing, the frequency of interrogation can beconsiderably higher than that of the tire monitor, for example. However,if the seat is unoccupied, then the frequency of interrogation can besubstantially reduced. For an occupied seat, information as to theidentity and/or category and position of an occupying item of the seatcan be obtained through the multiple weight sensors described. For thisreason, and due to the fact that during the pre-crash event, theposition of an occupying item of the seat may be changing rapidly,interrogations as frequently as once every 10 milliseconds or faster canbe desirable. This would also enable a distribution of the weight beingapplied to the seat to be obtained which provides an estimation of thecenter of pressure and thus the position of the object occupying theseat. Using pattern recognition technology, e.g., a trained neuralnetwork, sensor fusion, fuzzy logic, etc., an identification of theobject can be ascertained based on the determined weight and/ordetermined weight distribution.

There are many other methods by which SAW devices can be used todetermine the weight and/or weight distribution of an occupying itemother than the method described above and all such uses of SAW strainsensors for determining the weight and weight distribution of anoccupant are contemplated. For example, SAW devices with appropriatestraps can be used to measure the deflection of the seat cushion top orbottom caused by an occupying item, or if placed on the seat belts, theload on the belts can determined wirelessly and powerlessly. Geometriessimilar to those disclosed in U.S. Pat. No. 6,242,701 (which disclosesmultiple strain gage geometries) using SAW strain-measuring devices canalso be constructed, e.g., any of the multiple strain gage geometriesshown therein.

Generally there is an RFID implementation, which may contain anassociated sensor that corresponds to each SAW implementation.Therefore, where SAW is used herein the equivalent RFID design will alsobe meant where appropriate.

Although a preferred method for using the invention is to interrogateeach SAW device using wireless mechanisms, in some cases, it may bedesirable to supply power to and/or obtain information from one or moreof the SAW devices using wires. As such, the wires would be an optionalfeature.

One advantage of the weight sensors of this invention along with thegeometries disclosed in the '701 patent and herein below, is that inaddition to the axial stress in the seat support, the bending moments inthe structure can be readily determined. For example, if a seat issupported by four “legs”, it is possible to determine the state ofstress, assuming that axial twisting can be ignored, using four straingages on each leg support for a total of 16 such gages. If the seat issupported by three legs, then this can be reduced to 12 gages. Athree-legged support is preferable to four since with four legs, theseat support is over-determined which severely complicates thedetermination of the stress caused by an object on the seat. Even withthree supports, stresses can be introduced depending on the nature ofthe support at the seat rails or other floor-mounted supportingstructure. If simple supports are used that do not introduce bendingmoments into the structure, then the number of gages per seat can bereduced to three, provided a good model of the seat structure isavailable. Unfortunately, this is usually not the case and most seatshave four supports and the attachments to the vehicle not only introducebending moments into the structure but these moments vary from oneposition to another and with temperature. The SAW strain gages of thisinvention lend themselves to the placement of multiple gages onto eachsupport as needed to approximately determine the state of stress andthus the weight of the occupant depending on the particular vehicleapplication. Furthermore, the wireless nature of these gages greatlysimplifies the placement of such gages at those locations that are mostappropriate.

An additional point should be mentioned. In many cases, thedetermination of the weight of an occupant from the static strain gagereadings yields inaccurate results due to the indeterminate stress statein the support structure. However, the dynamic stresses to a first orderare independent of the residual stress state. Thus, the change in stressthat occurs as a vehicle travels down a roadway caused by dips in theroadway can provide an accurate measurement of the weight of an objectin a seat. This is especially true if an accelerometer is used tomeasure the vertical excitation provided to the seat.

Some vehicle models provide load leveling and ride control functionsthat depend on the magnitude and distribution of load carried by thevehicle suspension. Frequently, wire strain gage technology is used forthese functions. That is, the wire strain gages are used to sense theload and/or load distribution of the vehicle on the vehicle suspensionsystem. Such strain gages can be advantageously replaced with straingages based on SAW technology with the significant advantages in termsof cost, wireless monitoring, dynamic range, and signal level. Inaddition, SAW strain gage systems can be more accurate than wire straingage systems.

A strain detector in accordance with this invention can convertmechanical strain to variations in electrical signal frequency with alarge dynamic range and high accuracy even for very small displacements.The frequency variation is produced through use of a surface acousticwave (SAW) delay line as the frequency control element of an oscillator.A SAW delay line comprises a transducer deposited on a piezoelectricmaterial such as quartz or lithium niobate which is arranged so as to bedeformed by strain in the member which is to be monitored. Deformationof the piezoelectric substrate changes the frequency controlcharacteristics of the surface acoustic wave delay line, therebychanging the frequency of the oscillator. Consequently, the oscillatorfrequency change is a measure of the strain in the member beingmonitored and thus the weight applied to the seat. A SAW straintransducer can be more accurate than a conventional resistive straingage.

Other applications of weight measuring systems for an automobile includemeasuring the weight of the fuel tank or other containers of fluid todetermine the quantity of fluid contained therein as discussed below.

One problem with SAW devices is that if they are designed to operate atthe GHz frequency, the feature sizes become exceeding small and thedevices are difficult to manufacture, although techniques are nowavailable for making SAW devices in the tens of GHz range. On the otherhand, if the frequencies are considerably lower, for example, in thetens of megahertz range, then the antenna sizes become excessive. It isalso more difficult to obtain antenna gain at the lower frequencies.This is also related to antenna size. One method of solving this problemis to transmit an interrogation signal in the high GHz range which ismodulated at the hundred MHz range. At the SAW transducer, thetransducer is tuned to the modulated frequency. Using a nonlinear devicesuch as a Shocky diode, the modified signal can be mixed with theincoming high frequency signal and re-transmitted through the sameantenna. For this case, the interrogator can continuously broadcast thecarrier frequency.

Devices based on RFID or SAW technology can be used as switches in avehicle as described in U.S. Pat. Nos. 6,078,252, 6,144,288 and6,748,797. There are many ways that this can be accomplished. A switchcan be used to connect an antenna to either an RFID electronic device orto a SAW device. This requires contacts to be closed by the switchactivation. An alternate approach is to use pressure from an occupant'sfinger, for example, to alter the properties of the acoustic wave on theSAW material much as in a SAW touch screen. The properties that can bemodified include the amplitude of the acoustic wave, and its phase,and/or the time delay or an external impedance connected to one of theSAW reflectors as disclosed in U.S. Pat. No. 6,084,503. In thisimplementation, the SAW transducer can contain two sections, one whichis modified by the occupant and the other which serves as a reference. Acombined signal is sent to the interrogator that decodes the signal todetermine that the switch has been activated. By any of thesetechnologies, switches can be arbitrarily placed within the interior ofan automobile, for example, without the need for wires. Since wires andconnectors are the cause of most warranty repairs in an automobile, notonly is the cost of switches substantially reduced but also thereliability of the vehicle electrical system is substantially improved.

The interrogation of switches can take place with moderate frequencysuch as once every 100 milliseconds. Either through the use of differentfrequencies or different delays, a large number of switches can be time,code, space and/or frequency multiplexed to permit separation of thesignals obtained by the interrogator. Alternately, an RF activatedswitch on some or all of the sensors can be used as discussed below.

Another approach is to attach a variable impedance device across one ofthe reflectors on the SAW device. The impedance can therefore be used todetermine the relative reflection from the reflector compared to otherreflectors on the SAW device. In this manner, the magnitude as well asthe presence of a force exerted by an occupant's finger, for example,can be used to provide a rate sensitivity to the desired function. In analternate design, as shown in U.S. Pat. No. 6,144,288, the switch isused to connect the antenna to the SAW device. In this case, theinterrogator will not get a return from the SAW switch unless it isdepressed.

Temperature measurement is another field in which SAW technology can beapplied and the invention encompasses several embodiments of SAWtemperature sensors.

U.S. Pat. No. 4,249,418 is one of many examples of prior art SAWtemperature sensors. Temperature sensors are commonly used withinvehicles and many more applications might exist if a low cost wirelesstemperature sensor is available such as disclosed herein. The SAWtechnology can be used for such temperature sensing tasks. These tasksinclude measuring the vehicle coolant temperature, air temperaturewithin passenger compartment at multiple locations, seat temperature foruse in conjunction with seat warming and cooling systems, outsidetemperatures and perhaps tire surface temperatures to provide earlywarning to operators of road freezing conditions. One example, is toprovide air temperature sensors in the passenger compartment in thevicinity of ultrasonic transducers used in occupant sensing systems asdescribed in U.S. Pat. No. 5,943,295, since the speed of sound in theair varies by approximately 20% from −40° C. to 85° C. Currentultrasonic occupant sensor systems do not measure or compensate for thischange in the speed of sound with the effect of reducing the accuracy ofthe systems at the temperature extremes. Through the judicious placementof SAW temperature sensors in the vehicle, the passenger compartment airtemperature can be accurately estimated and the information providedwirelessly to the ultrasonic occupant sensor system thereby permittingcorrections to be made for the change in the speed of sound.

Since the road can be either a source or a sink of thermal energy,strategically placed sensors that measure the surface temperature of atire can also be used to provide an estimate of road temperature.

Acceleration sensing is another field in which SAW technology can beapplied and the invention encompasses several embodiments of SAWaccelerometers.

U.S. Pat. Nos. 4,199,990, 4,306,456 and 4,549,436 are examples of priorart SAW accelerometers. Airbag crash sensors for determining whether thevehicle is experiencing a frontal or side impact often use micromachinedaccelerometers. These accelerometers are usually based on the deflectionof a mass which is sensed using either capacitive or piezoresistivetechnologies. SAW technology has previously not been used as a vehicleaccelerometer or for vehicle crash sensing. Due to the importance ofthis function, at least one interrogator could be dedicated to thiscritical function. Acceleration signals from the crash sensors should bereported at least preferably every 100 microseconds. In this case, thededicated interrogator would send an interrogation pulse to all crashsensor accelerometers every 100 microseconds and receive staggeredacceleration responses from each SAW accelerometer wirelessly. Thistechnology permits the placement of multiple low-cost accelerometers atideal locations for crash sensing including inside the vehicle sidedoors, in the passenger compartment and in the frontal crush zone.Additionally, crash sensors can now be located in the rear of thevehicle in the crush zone to sense rear impacts. Since the accelerationdata is transmitted wirelessly, concern about the detachment or cuttingof wires from the sensors disappears. One of the main concerns, forexample, of placing crash sensors in the vehicle doors where they mostappropriately can sense vehicle side impacts, is the fear that an impactinto the A-pillar of the automobile would sever the wires from thedoor-mounted crash sensor before the crash was sensed. This problemdisappears with the wireless technology of this invention. If twoaccelerometers are placed at some distance from each other, the rollacceleration of the vehicle can be determined and thus the tendency ofthe vehicle to rollover can be predicted in time to automatically takecorrective action and/or deploy a curtain airbag or other airbag(s).Other types of sensors such as crash sensors based on pressuremeasurements, such as supplied by Siemens, can also now be wireless.

Although the sensitivity of measurement is considerably greater thanthat obtained with conventional piezoelectric or micromachinedaccelerometers, the frequency deviation of SAW devices remains low (inabsolute value). Accordingly, the frequency drift of thermal originshould be made as low as possible by selecting a suitable cut of thepiezoelectric material. The resulting accuracy is impressive aspresented in U.S. Pat. No. 4,549,436, which discloses an angularaccelerometer with a dynamic a range of 1 million, temperaturecoefficient of 0.005%/deg F, an accuracy of 1 microradian/sec², a powerconsumption of 1 milliwatt, a drift of 0.01% per year, a volume of 1cc/axis and a frequency response of 0 to 1000 Hz. The subject matter ofthe '436 patent is hereby included in the invention to constitute a partof the invention. A similar design can be used for acceleration sensing.

In a similar manner as the polymer-coated SAW device is used to measurepressure, a device wherein a seismic mass is attached to a SAW devicethrough a polymer interface can be made to sense acceleration. Thisgeometry has a particular advantage for sensing accelerations below 1 G,which has proved to be very difficult for conventional micro-machinedaccelerometers due to their inability to both measure low accelerationsand withstand high acceleration shocks.

Gyroscopes are another field in which SAW technology can be applied andthe inventions herein encompass several embodiments of SAW gyroscopes.

SAW technology is particularly applicable for gyroscopes as described inInternational Publication No. WO 00/79217A2. The output of suchgyroscopes can be determined with an interrogator that is also used forthe crash sensor accelerometers, or a dedicated interrogator can beused. Gyroscopes having an accuracy of approximately 1 degree per secondhave many applications in a vehicle including skid control and otherdynamic stability functions. Additionally, gyroscopes of similaraccuracy can be used to sense impending vehicle rollover situations intime to take corrective action.

The inventor has represented that SAW gyroscopes of the type describedin WO 00/79217A2 have the capability of achieving accuracies approachingabout 3 degrees per hour. This high accuracy permits use of suchgyroscopes in an inertial measuring unit (IMU) that can be used withaccurate vehicle navigation systems and autonomous vehicle control basedon differential GPS corrections. Such a system is described in U.S. Pat.No. 6,370,475. An alternate preferred technology for an IMU is describedin U.S. Pat. No. 4,711,125. Such navigation systems depend on theavailability of four or more GPS satellites and an accurate differentialcorrection signal such as provided by the OmniStar Corporation, NASA orthrough the National Differential GPS system now being deployed. Theavailability of these signals degrades in urban canyon environments, intunnels and on highways when the vehicle is in the vicinity of largetrucks. For this application, an IMU system should be able to accuratelycontrol the vehicle for perhaps 15 seconds and preferably for up to fiveminutes. IMUs based on SAW technology, the technology of U.S. Pat. No.4,549,436 or of U.S. Pat. No. 4,711,125 are the best-known devicescapable of providing sufficient accuracies for this application at areasonable cost. Other accurate gyroscope technologies such as fiberoptic systems are more accurate but can be cost-prohibitive, althoughanalysis has indicated that such gyroscopes can eventually be madecost-competitive. In high volume production, an IMU of the requiredaccuracy based on SAW technology is estimated to cost less than about$100. A cost competing technology is that disclosed in U.S. Pat. No.4,711,125 which does not use SAW technology.

What follows is a discussion of the Morrison Cube of U.S. Pat. No.4,711,125 known as the QUBIK™. Typical problems that are encounteredwith sensors that try to measure multiple physical quantities at thesame time and how the QUBIK solves these problems are set forth below.

1. Problem: Errors of measurement of the linear accelerations andangular speed are mutually correlated. Even if every one of the errors,taken separately, does not accumulate with integration (the inertialsystem's algorithm does that), the cross-coupled multiplication (such asone during re-projecting the linear accelerations from one coordinatesystem to another) will have these errors detected and will make them asystematic error similar to a sensor's bias.

Solution: The QUBIK IMU is calibrated and compensated for any cross axissensitivity. For example: if one of the angular accelerometer channelshas a sensitivity to any of the three of linear accelerations, then thelinear accelerations are buffered and scaled down and summed with thebuffered angular accelerometer output to cancel out all linearacceleration sensitivity on all three angular accelerometer channels.This is important to detect pure angular rate signals. This is a verycommon practice throughout the U.S. aerospace industry to makenavigation grade IMU's. Even when individual gyroscopes andaccelerometers are used in navigation, they have their outputs scaledand summed together to cancel out these cross axis errors. Note thatcompetitive MEMS products have orders of magnitude higher cross axissensitivities when compared to navigation grade sensors and they willundoubtedly have to use this practice to improve performance. MEMSangular rate sensors are advertised in degrees per second and navigationangular rate sensors are advertised in degrees per hour. MEMS angularrate sensors have high linear acceleration errors that must becompensated for at the IMU level.

2. Problem: The gyroscope and accelerometer channels require settings tobe made that contradict one another physically. For example, a gapbetween the cube and the housing for the capacitive sensors (thatmeasure the displacements of the cube) is not to exceed 50 to 100microns. On the other hand, the gyroscope channels require, in order toenhance a Coriolis effect used to measure the angular speed, that theamplitude and the linear speed of vibrations are as big as possible. Todo this, the gap and the frequency of oscillations should be increased.A greater frequency of oscillations in the nearly resonant mode requiresthe stiffness of the electromagnetic suspension to be increased, too,which leads to a worse measurement of the linear accelerations becausethe latter require that the rigidity of the suspension be minimal whenthere is a closed feedback.

Solution: The capacitive gap all around the levitated inner cube of theQUBIK is nominally 0.010 inches. The variable capacitance plates areexcited by a 1.5 MHz 25 volt peak to peak signal. The signal coming outis so strong (five volts) that there is no preamp required. Diodedetectors are mounted directly above the capacitive plates. There is noperformance change in the linear accelerometer channels when the angularaccelerometer channels are being dithered or rotated back and forthabout an axis. This was discovered by having a ground plane around theelectromagnets that eliminated transformer coupling. Dithering ordriving the angular accelerometer which rotates the inner cube proofmass is a gyroscopic displacement and not a linear displacement and hasno effect on the linear channels. Another very important point to makeis the servo loops measure the force required to keep the inner cube atits null and the servo loops are integrated to prevent anydisplacements. The linear accelerometer servo loops are not beingexercised to dither the inner cube. The angular accelerometer servo loopis being exercised. The linear and angular channels have their ownseparate set of capacitance detectors and electromagnets. Driving theangular channels has no effect on the linear ones.

The rigidity of an integrated closed loop servo is infinite at DC androlls off at higher frequencies. The QUBIK IMU measures the force beingapplied to the inner cube and not the displacement to measure angularrate. There is a force generated on the inner cube when it is beingrotated and the servo will not allow any displacement by applying equaland opposite forces on the inner cube to keep it at null. The servoreadout is a direct measurement of the gyroscopic forces on the innercube and not the displacement.

The servo gain is so high at the null position that one will not see thenull displacement but will see a current level equivalent to the forceon the cube. This is why integrated closed loop servos are so good. Theymeasure the force required to keep the inner cube at null and not thedisplacement. The angular accelerometer channel that is being ditheredwill have a noticeable displacement at its null. The sensor does nothave to be driven at its resonance. Driving the angular accelerometer atresonance will run the risk of over-driving the inner cube to the pointwhere it will bottom out and bang around inside its cavity. There is anactive gain control circuit to keep the alternating momentum constant.

Note that competitive MEMS based sensors are open loop and allowdisplacements which increase cross axis errors. MEMS sensors must havedisplacements to work and do not measure the Coriolis force, theymeasure displacement which results in huge cross axis sensitivityissues.

3. Problem: As the electromagnetic suspension is used, the sensor isgoing to be sensitive to external constant and variable (alternating)fields. Its errors will vary with its position, for example, withrespect to the Earth's magnetic field or other magnetic sources.

Solution: The earths magnetic field varies from −0.0 to +0.3 gauss andthe magnets have gauss levels over 10,000. The earth field can beshielded if necessary.

4. Problem: The QUBIT sensing element is relatively heavy so the sensoris likely to be sensitive to angular accelerations and impacts. Also,the temperature of the environment can affect the micron-sized gaps,magnetic fields of the permanent magnets, the resistance of theinductance coils etc., which will eventually increase the sensor errors.

Solution: The inner cube has a gap of 0.010 inches and does not changesignificantly over temperature.

The resistance of the coils is not a factor in the active closed loopservo. Anybody who make this statement does not know what they aretalking about. There is a stable one PPM/C current readout resistor inseries with the coil that measures the current passing through the coilwhich eliminates the temperature sensitivity of the coil resistance.

Permanent magnets have already proven themselves to be very stable overtemperature when used in active servo loops used in navigationgyroscopes and accelerometers.

Note that the sensitivity that the QUBIK IMU has achieved 0.01 degreesper hour.

5. Problem: High Cost. To produce the QUBIK, one may need to maintainmicron-sized gaps and highly clean surfaces for capacitive sensors; thedevices must be assembled in a dust-free room, and the device itselfmust be hermetic (otherwise dust or moisture will put the capacitivesensor and the electromagnetic suspension out of operation), thepermanent magnets must have a very stable performance because they'regoing to work in a feedback circuit, and so on. In our opinion, allthese issues make the technology overly complex and expensive, so anadditional metrological control will be required and no full automationcan be ever done.

Solution: The sensor does not have micron size gaps and does not need tobe hermetic unless the sensor is submerged in water! Most of the QUBIKIMU sensor is a cut out PCB's that can certainly be automated. The PCBdesign can keep dust out and does not need to be hermetic. Humidity isnot a problem unless the sensor is submerged in water. The permanentmagnets achieve parts per million stability at a cost of about $0.05each for a per system cost of under one dollar. There are may navigationgrade gyroscopes and accelerometers that use permanent magnets.

Competitive MEMS sensors can have process contamination problems. To myknowledge, there are no MEMS angular rate sensors that do not requirehuman labor and/or calibration. The QUBIK IMU can instead useprogrammable potentiometers at calibration instead of human labor.

Once an IMU of the accuracy described above is available in the vehicle,this same device can be used to provide significant improvements tovehicle stability control and rollover prediction systems.

Keyless entry systems are another field in which SAW technology can beapplied and the invention encompasses several embodiments of accesscontrol systems using SAW devices.

A common use of SAW or RFID technology is for access control tobuildings however, the range of electronic unpowered RFID technology isusually limited to one meter or less. In contrast, the SAW technology,when powered or boosted, can permit sensing up to about 30 meters. As akeyless entry system, an automobile can be configured such that thedoors unlock as the holder of a card containing the SAW ID systemapproaches the vehicle and similarly, the vehicle doors can beautomatically locked when the occupant with the card travels beyond acertain distance from the vehicle. When the occupant enters the vehicle,the doors can again automatically lock either through logic or through acurrent system wherein doors automatically lock when the vehicle isplaced in gear. An occupant with such a card would also not need to havean ignition key. The vehicle would recognize that the SAW-based card wasinside vehicle and then permit the vehicle to be started by issuing anoral command if a voice recognition system is present or by depressing abutton, for example, without the need for an ignition key.

SAW sensors operating in the wireless mode can also be used to sense forice on the windshield or other exterior surfaces of the vehicle,condensation on the inside of the windshield or other interior surfaces,rain sensing, heat-load sensing and many other automotive sensingfunctions. They can also be used to sense outside environmentalproperties and states including temperature, humidity, etc.

SAW sensors can be economically used to measure the temperature andhumidity at numerous places both inside and outside of a vehicle. Whenused to measure humidity inside the vehicle, a source of water vapor canbe activated to increase the humidity when desirable and the airconditioning system can be activated to reduce the humidity whennecessary or desirable. Temperature and humidity measurements outside ofthe vehicle can be an indication of potential road icing problems. Suchinformation can be used to provide early warning to a driver ofpotentially dangerous conditions. Although the invention describedherein is related to land vehicles, many of these advances are equallyapplicable to other vehicles such as airplanes and even, in some cases,homes and buildings. The invention disclosed herein, therefore, is notlimited to automobiles or other land vehicles.

Road condition sensing is another field in which SAW technology can beapplied and the invention encompasses several embodiments of SAW roadcondition sensors.

The temperature and moisture content of the surface of a roadway arecritical parameters in determining the icing state of the roadway.Attempts have been made to measure the coefficient of friction between atire and the roadway by placing strain gages in the tire tread. Suchstrain gages are ideal for the application of SAW technology especiallysince they can be interrogated wirelessly from a distance and theyrequire no power for operation. As discussed herein, SAW accelerometerscan also perform this function. Measurement of the friction coefficient,however, is not predictive and the vehicle operator is only able toascertain the condition after the fact. Boosted SAW or RFID basedtransducers have the capability of being interrogated as much as 100feet from the interrogator. Therefore, judicious placement of low-costSAW or RFID temperature and humidity sensors in and/or on the roadway atcritical positions can provide an advance warning to vehicle operatorsthat the road ahead is slippery. Such devices are very inexpensive andtherefore could be placed at frequent intervals along a highway.

An infrared sensor that looks down the highway in front of the vehiclecan actually measure the road temperature prior to the vehicle travelingon that part of the roadway. This system also would not give sufficientwarning if the operator waited for the occurrence of a frozen roadway.The probability of the roadway becoming frozen, on the other hand, canbe predicted long before it occurs, in most cases, by watching the trendin the temperature. Once vehicle-to-vehicle andvehicle-to-infrastructure communications are common, roadway icingconditions can be communicated between vehicles or, preferably, to theinternet and thereafter to all vehicles in the vicinity. Wi-Fi and inparticular WiMAX is currently being implemented and will becomeubiquitous over time, permitting the transfer of such information tovehicles entering the affected area even though the vehicles that sensedthe condition are no longer in the vicinity.

Some lateral control of the vehicle can also be obtained from SAWtransducers or electronic RFID tags placed down the center of the lane,either above the vehicles and/or in the roadway, for example, perhaps inlane-mounted reflectors. A vehicle having two receiving antennas, forexample, approaching such devices, through triangulation or directproportion, is able to determine the lateral location of the vehiclerelative to these SAW devices. If the vehicle also has an accurate mapof the roadway, the identification number associated with each suchdevice can be used to obtain highly accurate longitudinal positiondeterminations. Ultimately, the SAW devices can be placed on structuresbeside the road and perhaps on every mile or tenth of a mile marker. Ifthree antennas are used, as discussed herein, the distances from thevehicle to the SAW device can be determined. These SAW devices can bepowered in order to stay below current FCC power transmission limits.Such power can be supplied by a photocell, energy harvesting whereapplicable, by a battery or power connection.

Electronic RFID tags are also suitable for lateral and longitudinalpositioning purposes, however, the range available for currentelectronic RFID systems can be less than that of SAW-based systemsunless either are powered. On the other hand, as disclosed in U.S. Pat.No. 6,748,797, the time-of-flight of the RFID system can be used todetermine the distance from the vehicle to the RFID tag. Because of theinherent delay in the SAW devices and its variation with temperature,accurate distance measurement is probably not practical based ontime-of-flight but somewhat less accurate distance measurements based onrelative time-of-arrival can be made. Even if the exact delay imposed bythe SAW device was accurately known at one temperature, such devices areusually reasonably sensitive to changes in temperature, hence they makegood temperature sensors, and thus the accuracy of the delay in the SAWdevice is more difficult to maintain. An interesting variation of anelectronic RFID that is particularly applicable to this and otherapplications of this invention is described in A. Pohl, L. Reindl, “Newpassive sensors”, Proc. 16th IEEE Instrumentation and MeasurementTechnology Conf., IMTC/99, 1999, pp. 1251-1255.

Many SAW devices are based on lithium niobate or similar strongpiezoelectric materials. Such materials have high thermal expansioncoefficients. An alternate material is quartz that has a very lowthermal expansion coefficient. However, its piezoelectric properties areinferior to lithium niobate. One solution to this problem is to uselithium niobate as the coupling system between the antenna and thematerial or substrate upon which the surface acoustic wave travels. Inthis manner, the advantages of a low thermal expansion coefficientmaterial can be obtained while using the lithium niobate for its strongpiezoelectric properties. Other useful materials such as Langasite™ haveproperties that are intermediate between lithium niobate and quartz.

The use of SAW tags as an accurate precise positioning system asdescribed above would be applicable for accurate vehicle location, asdiscussed in U.S. Pat. No. 6,370,475, for lanes in tunnels, for example,or other cases where loss of satellite lock, and thus the primaryvehicle location system, is common.

The various technologies discussed above can be used in combination. Theelectronic RFID tag can be incorporated into a SAW tag providing asingle device that provides both a quick reflection of the radiofrequency waves as well as a re-transmission at a later time. Thismarriage of the two technologies permits the strengths of eachtechnology to be exploited in the same device. For most of theapplications described herein, the cost of mounting such a tag in avehicle or on the roadway far exceeds the cost of the tag itself.Therefore, combining the two technologies does not significantly affectthe cost of implementing tags onto vehicles or roadways or side highwaystructures. An alternative is to use a corner cube or dihedral reflectorfor ranging and an RFID or SAW for identification.

A variation of this design is to use an RF circuit such as in an RFID toserve as an energy source. One design could be for the RFID to operatewith directional antennas at a relatively high frequency such as 2.4GHz. This can be primarily used to charge a capacitor to provide theenergy for boosting the signal from the SAW sensor using circuitry suchas a circulator discussed below. The SAW sensor can operate at a lowerfrequency, such as 400 MHz, permitting it to not interfere with theenergy transfer to the RF circuit and also permit the signal to travelbetter to the receiver since it will be difficult to align the antennaat all times with the interrogator. Also, by monitoring the reception ofthe RF signal, the angular position of the tire can be determined andthe SAW circuit designed so that it only transmits when the antennas arealigned or when the vehicle is stationary. Many other opportunities nowpresent themselves with the RF circuit operating at a differentfrequency from the SAW circuit which will now be obvious to one skilledin the art.

An alternate method to the electronic RFID tag is to simply use a radaror lidar reflector and measure the time-of-flight to the reflector andback. The reflector can even be made of a series of reflecting surfacesdisplaced from each other to achieve some simple coding. It should beunderstood that RFID antennas can be similarly configured. Animprovement would be to polarize the radiation and use a reflector thatrotates the polarization angle, known as a dihedral reflector, allowingthe reflector to be more easily found among other reflecting objects.

FIG. 11 illustrates a vehicle passenger compartment, and the enginecompartment, with multiple SAW or RFID temperature sensors 85. SAWtemperature sensors can be distributed throughout the passengercompartment, such as on the A-pillar, on the B-pillar, on the steeringwheel, on the seat, on the ceiling, on the headliner, and on thewindshield, rear and side windows and generally in the enginecompartment. These sensors, which can be independently coded withdifferent IDs and/or different delays, can provide an accuratemeasurement of the temperature distribution within the vehicle interior.RFID switches can also be used to isolate one device from another. Sucha system can be used to tailor the heating and air conditioning systembased on the temperature at a particular location in the passengercompartment. If this system is augmented with occupant sensors, then thetemperature can be controlled based on seat occupancy and thetemperature at that location. If the occupant sensor system is based onultrasonics, then the temperature measurement system can be used tocorrect the ultrasonic occupant sensor system for the speed of soundwithin the passenger compartment. Without such a correction, the errorin the sensing system can be as large as about 20 percent.

The SAW temperature sensors 85 provide the temperature at their mountinglocation to a processor unit 83 via an interrogator with the processorunit 83 including appropriate control algorithms for controlling theheating and air conditioning system based on the detected temperatures.The processor unit 83 can control, e.g., which vents in the vehicle areopen and closed, the flow rate through vents and the temperature of airpassing through the vents. In general, the processor unit 83 can controlwhatever adjustable components are present or form part of the heatingand air conditioning system.

All of the elements of the system which adjusts or controls the vehiclecomponents in any of the embodiments described herein, i.e., thesensors, processing unit and reactive system which is controlled by theprocessing unit based on the data sensed by the sensors, can be arrangedwithin the vehicle. They could be fixed to the frame of the vehicle,and/or arranged in an interior defined by the frame, with the sensorassemblies (the sensor and wireless transmission component associatedtherewith) fixed relative to the processor unit or receiver whichcontains the antenna capable of receiving the signals being transmittedwirelessly from the wireless transmission component of the sensorassemblies. In some embodiments, the sensor assemblies are arranged onparts of the vehicle which are not fixed to the frame or fixed relativeto the processor unit or receiver, such as on the tires, but in otherembodiments, the sensor assemblies are arranged only on parts fixed tothe frame. This fixed relationship between the sensor assemblies and thereceiver(s) associated with the processing unit allows for properpositioning of the receivers to communicate with all designated sensorassemblies.

In FIG. 11, a child seat 87 is illustrated on the rear vehicle seat. Thechild seat 87 can be fabricated with one or more RFID tags or SAW tags(not shown). The RFID and SAW tag(s) can be constructed to provideinformation on the occupancy of the child seat, i.e., whether a child ispresent, based on the weight, temperature, and/or any other measurableparameter. Also, the mere transmission of waves from the RFID or SAWtag(s) on the child seat 87 would be indicative of the presence of achild seat. The RFID and SAW tag(s) can also be constructed to provideinformation about the orientation of the child seat 87, i.e., whether itis facing rearward or forward. Such information about the presence andoccupancy of the child seat and its orientation can be used in thecontrol of vehicular systems, such as the vehicle airbag system orheating or air conditioning system, especially useful when a child isleft in a vehicle. In this case, a processor would control the airbag orHVAC system and would receive information from the RFID and SAW tag(s)via an interrogator.

SAW sensors also have applicability to various other sectors of thevehicle, including the powertrain, chassis, and occupant comfort andconvenience. For example, SAW and RFID sensors have applicability tosensors for the powertrain area including oxygen sensors, gear-toothHall effect sensors, variable reluctance sensors, digital speed andposition sensors, oil condition sensors, rotary position sensors, lowpressure sensors, manifold absolute pressure/manifold air temperature(MAP/MAT) sensors, medium pressure sensors, turbo pressure sensors,knock sensors, coolant/fluid temperature sensors, and transmissiontemperature sensors.

SAW sensors for chassis applications include gear-tooth Hall effectsensors, variable reluctance sensors, digital speed and positionsensors, rotary position sensors, non-contact steering position sensors,and digital ABS (anti-lock braking system) sensors. In oneimplementation, a Hall Effect tire pressure monitor comprises a magnetthat rotates with a vehicle wheel and is sensed by a Hall Effect devicewhich is attached to a SAW or RFID device that is wirelesslyinterrogated. This arrangement eliminates the need to run a wire intoeach wheel well.

FIG. 12 illustrates the placement of a variety of sensors, primarilyaccelerometers and/or gyroscopes, which can be used to diagnose thestate of the vehicle itself. Sensor 105 can be located in the headlineror attached to the vehicle roof above the side door. Typically, therecan be two such sensors one on either side of the vehicle. Sensor 106 isshown in a typical mounting location midway between the sides of thevehicle attached to or near the vehicle roof above the rear window.Sensor 109 is shown in a typical mounting location in the vehicle trunkadjacent the rear of the vehicle. One, two or three such sensors can beused depending on the application. If three such sensors are used,preferably one would be adjacent each side of vehicle and one in thecenter. Sensor 107 is shown in a typical mounting location in thevehicle door and sensor 108 is shown in a typical mounting location onthe sill or floor below the door. Sensor 110, which can be also multiplesensors, is shown in a typical mounting location forward in the crushzone of the vehicle. Finally, sensor 111 can measure the acceleration ofthe firewall or instrument panel and is located thereon generally midwaybetween the two sides of the vehicle. If three such sensors are used,one would be adjacent each vehicle side and one in the center. An IMUwould serve basically the same functions at lower installation cost.

In general, sensors 105-111 provide a measurement of the state of thevehicle, such as its velocity, acceleration, angular orientation ortemperature, or a state of the location at which the sensor is mounted.Thus, measurements related to the state of the sensor would includemeasurements of the acceleration of the sensor, measurements of thetemperature of the mounting location as well as changes in the state ofthe sensor and rates of changes of the state of the sensor. As such, anydescribed use or function of the sensors 105-111 above is merelyexemplary and is not intended to limit the form of the sensor or itsfunction. Thus, these sensors may or may not be SAW or RFID sensors andmay be powered or unpowered and may transmit their information through awire harness, a safety or other bus or wirelessly.

Each sensor 105-111 may be single axis, double axis or triaxialaccelerometers and/or gyroscopes typically of the MEMS type. One or morecan be IMUs. These sensors 105-111 can either be wired to the centralcontrol module or processor directly wherein they would receive powerand transmit information, or they could be connected onto the vehiclebus or, in some cases, using RFID, SAW or similar technology, thesensors can be wireless and would receive their power through RF fromone or more interrogators located in the vehicle. In this case, theinterrogators can be connected either to the vehicle bus or directly tocontrol module. Alternately, an inductive or capacitive power and/orinformation transfer system can be used.

The driver can be provided with a keyless entry device, other RFID tag,smart card or cell phone with an RF transponder that can be powerless inthe form of an RFID or similar device, which can also be boosted asdescribed herein. Generally, such keyless entry devices can beconsidered a portable identification device. The interrogator, or aprocessing unit associated therewith, determines the proximity of thedriver to the vehicle door or other similar object such as a building orhouse door or vehicle trunk. As shown in FIG. 13, if a driver 118remains within a certain distance, 1 meter for example, from the door ortrunk lid 116, for example, for a certain time period such as 5 seconds,then the door or trunk lid 116 can automatically unlock and ever open insome implementations. The distance and time period can be selected ordetermined as desired. Thus, as the driver 118 approaches the trunk withhis or her arms filled with packages 117 and pauses, the trunk canautomatically open (see FIG. 14). Such a system would be especiallyvaluable for older people. This system can also be used for othersystems in addition to vehicle doors and trunk lids.

As shown in FIG. 15, an interrogator 115 is placed on the vehicle, e.g.,in the trunk 112 as shown, and transmits waves. When the keyless entrydevice 113, which contains an antenna 114 and a circuit including acirculator 135 and a memory containing a unique ID code 136, is a setdistance from the interrogator 115 for a certain duration of time, theinterrogator 115 directs a trunk opening device 137 to open the trunklid 116. The duration of time is determined from the continuousreception by the interrogator 115 of the ID code 136 from the keylessentry device 113.

A SAW device can also be used as a wireless switch as shown in FIGS. 16Aand 16B. FIG. 16A illustrates a surface 120 containing a projection 122on top of a SAW device 121. Surface material 120 could be, for example,the armrest of an automobile, the steering wheel airbag cover, or anyother surface within the passenger compartment of an automobile orelsewhere. Projection 122 will typically be a material capable oftransmitting force to the surface of SAW device 121. As shown in FIG.16B, a projection 123 may be placed on top of the SAW device 124. Thisprojection 123 permits force exerted on the projection 122 to create apressure on the SAW device 124. This increased pressure changes the timedelay or natural frequency of the SAW wave traveling on the surface ofmaterial. Alternately, it can affect the magnitude of the returnedsignal. The projection 123 is typically held slightly out of contactwith the surface until forced into contact with it.

An alternate approach is to place a switch across the IDT 127 as shownin FIG. 16C. If switch 125 is open, then the device will not return asignal to the interrogator. If it is closed, than the IDT 127 will actas a reflector sending a signal back to IDT 128 and thus to theinterrogator. Alternately, a switch 126 can be placed across the SAWdevice. In this case, a switch closure shorts the SAW device and nosignal is returned to the interrogator. For the embodiment of FIG. 16C,using switch 126 instead of switch 125, a standard reflector IDT wouldbe used in place of the IDT 127.

FIG. 16D shows an embodiment wherein a radio-frequency identificationdevice (RFID) is controlled by a switch 129A, and may be one of thewireless transmission components of a switch assembly. The switch 129Amay be a conventional, mechanical switch such as a push button, toggleand the like. A switch assembly would therefore comprise the RFID, theswitch 129A and an antenna 119A which may constitute another wirelesstransmission component. In this case, when the user presses on anexposed surface of the passenger compartment, he or she would close theswitch 129A and thereby short the RFID so that it would be inoperative.That is, the RFID would not respond when interrogated. Instead of aswitch, a variable impedance could also be provided which would modifythe output of the RFID based on the magnitude of pressure to the exposedsurface. Instead of using the switch or variable impedance, anothercontrol mechanism for causing variation in the transmission by thewireless transmission components of the switch assembly can be provided.In this embodiment, as well as the other embodiments herein wherein anRFID is provided, the RFID can be either a passive RFID or an activeRFID. In the latter case, the RFID is supplied with power from a powersource on the vehicle, such as the vehicle's battery, a local battery,photo cell, or a local energy generator or harvester.

FIGS. 16C and 16D are examples of manually activated RFID switchassemblies which could be used in a vehicular component control systemto adjust various components based on user action. For example, eachswitch assembly could control a respective component with a processorunit of the control system being coupled to or included within aninterrogator arranged to transmit RF signals having identification dataassociated with the RFID switch assemblies such that upon transmissionof each RF signal, any RFID switch assemblies with matchingidentification data would be capable of providing responsive signals. Inparticular, the RFID switch assemblies provide output based on pressureapplied by the occupant of the vehicle to an exposed surface andincludes an RF transmission component arranged to wirelessly transmit anindication of the application of pressure to the exposed surface. Thisindication may be the magnitude of the pressure being applied (e.g., viathe switch assembly of FIG. 16C) or the absence of a signal (e.g., viathe short-circuited RFID of FIG. 16D). Other input devices for use inthe same component control system include those described elsewhereherein, for example, an RFID assembly including a sensor and an RFIDswitch which could receive an RF signal from the same interrogator andupon receipt of a signal containing its identification, enabletransmission of a signal from the sensor from which a property beingmonitored by the sensor is determinable. Another input device is an RFIDassembly including a sensor and an RFID switch which is arranged toreceive an RF signal from the same interrogator and upon receipt of asignal not containing its identification, disable transmission of an RFsignal from the interrogator to the sensor for its excitation, fromwhich sensor a property being monitored by the sensor is determinable.

FIG. 16H shows another switch assembly for controlling a component whichincludes an energy storage and/or transmission component 443 which maycomprise an RFID so that when the switch assembly is activated, the RFID443 is able to respond to an interrogation signal from an interrogatorassociated with the component control system. The RFID switch assemblyincludes a piezoelectric energy generator switch 441 underlying anexposed surface 440 of the vehicle and formed by a plurality of sheetsof a piezoelectric material, such as polyvinylidene fluoride (PVDF), andgenerates power upon application of pressure to the exposed surface 440.The generated power is usable to power the transmission component, i.e.,the RFID. The stack of PVDF sheets are placed over supports 442 and caninclude a snap action mechanism, not shown, to provide a snap actionswitch.

PVDF (Polyvinylidene fluoride) is a known inexpensive material capableof use in vehicles. PVDF is also usable as a SAW-type device and wouldbe especially applicable where there is external power provided. Thepresence of available energy could lead to certain advantages of the useof PVDF such as for chemical sensing since it could be much larger thanother sensing equivalents, such as lithium Niobate, and therefore morelikely to capture the chemical. As an energy generator, PVDF has muchmore applicability since a number of layers can be stacked therebymultiplying its energy output. The switch shown in FIG. 16H can be made,for example, so that it gets its power from someone snapping the stackof PVDF sheets 441 between supports 442 in a snap action switch. Thepower generated could send a signal to a receiver or alternatively, itcould be used to power the RFID 443 thereby giving an ID transmissionrelating to the switching action which is indicative of a desired actionby the occupant of the vehicle and thus could be used to control anadjustable component.

Such a PVDF switch could be used in those cases where a switching orsensing function covering a broad area is desired. The sensing of thecontact of the head with a headrest would be one example. In this case,the stack of PVDF sheets is arranged in the headrest below the coveringof the headrest and when an occupant rests his or her head against theheadrest, the PVDF sheets are compressed thereby generating power for anRFID to respond to an interrogator signal. The return signal to theinterrogator would therefore be indicative of the presence of anoccupant, or other object, resting against the headrest. Of course, manyother arrangements will be obvious to one skilled in the art.

FIG. 16E shows an embodiment wherein a surface-acoustic-wave (SAW)device is controlled by a switch 129B, and may be one of the wirelesstransmission components of a switch assembly. The switch 129B may be aconventional, mechanical switch such as a push button, toggle and thelike. A switch assembly would therefore comprise the SAW device, theswitch 129B and an antenna 119B which may constitute another a wirelesstransmission component. In this case, when the user presses on anexposed surface of the passenger compartment, he or she would close theswitch 129B and thereby prevent the SAW device from receiving a signalso that it would be inoperative. Instead of a switch, a variableimpedance could also be provided which would modify the output of theSAW device based on the magnitude of pressure to the exposed surface.Instead of using the switch or variable impedance, another controlmechanism for causing variation in the transmission by the wirelesstransmission components of the switch assembly can be provided. In thisembodiment, as well as the other embodiments herein wherein a SAW deviceis provided, the SAW device can be either a passive SAW device or anactive SAW device. In the latter case, the SAW device is supplied withpower from a power source on the vehicle, such as the vehicle's battery,a local battery or a local energy generator or harvester.

A variable impedance is used as the control mechanism for situationswhen variations in the operation of a vehicular component are desired.For example, if a light is capable of being dimmed, then the variableimpedance would be useful to control the dimming of the light. It isalso useful to control adjustment of the volume of a sound system in thevehicle, as well as other analogue functions.

Referring now to FIG. 16F, another embodiment of the invention using acontrol mechanism, i.e., a switch or variable impedance, is an antenna139 capable of reflecting an interrogating signal, and even whichslightly modifies the interrogating signal (reflection from such anantenna being termed backscatter). The modification to the interrogatingsignal can be correlated to the desired manner for controlling thevehicular component. In this case, a lead is connected to anintermediate location on the antenna 139, e.g., the middle of theantenna 139, and a switch or variable impedance (a switch 129C is shown)is placed between the lead and ground. In the embodiment having a switch129C, when the switch 129C is open, the antenna 139 will reflect at aparticular frequency based on its length (for a simple dipole antenna).When the switch 129C is closed by the application of pressure to theexposed surface 138 of the passenger compartment, the antenna 139 willshort and thereby effectively reduce the length of the antenna 139 andalter the resonant frequency of the antenna 139. A lead placed at themiddle of the antenna 139 would, when connected to a closed switch 129Cleading to ground, cause the resonant frequency to approximately double.In the embodiment having variable impedance, the antenna would beprovided with a variable effect depending on the pressure exerted on theexposed surface or otherwise controlling the variable impedance.

Referring now to FIG. 16G, in another embodiment of a SAW sensorassembly in accordance with the invention, the circuit of the SAW sensorassembly has both an active mode and a passive mode depending on thepresence of sufficient power in the energy storage device and whetherthe substrate to which the SAW sensor assembly is associated with ismoving and thereby generates energy (for example, the energy may begenerated using the power generating system described with reference toFIG. 9 herein and FIGS. 36, 36A and 98 of U.S. patent application Ser.No. 11/618,834 incorporated by reference herein). That is, the SAWsensor assembly circuit is provided with a passive mode, which is usedwhen power is not provided to the SAW device 158 by either an energyharvester or energy generating system and the substrate (tire) is notmoving, and an active mode when power is provided or available to theSAW device 158, e.g., provided by an energy harvester or energygenerating system upon rotation of the tire or from an energy storagedevice. In the active mode (when the tire is rotating or there issufficient power in the energy storage device to power the SAW device158), a power detection circuit 157 detects power and closes a switch129E thereby connecting the SAW device 158 to the antenna 119C. Powerdetection circuit 157 may be integrated into the SAW sensor assemblycircuit so that whenever there is sufficient power being generated oravailable, the switch 129E is automatically closed. On the other hand,when energy for the SAW device 158 is not provided by an energy storagedevice and the tire is not rotating, switch 129E is open so as to avoidproviding unnecessary signals from the SAW device 158 to theinterrogator via the antenna 119C, the interrogator being used to obtainthe signals from the SAW device 158 and process them into a meaningfulreading of whatever property or properties is/are being monitored by theSAW device 158. However, since it is desirable to provide signals fromthe SAW device 158 for certain conditions of the property beingmonitored by the SAW device 158, e.g., the property is below athreshold, a sensor 156 is provided and controls a second switch 129Dbetween the antenna 119C and the SAW device 158. Sensor 156 is designedto close the switch when one or more conditions relating to the propertyare satisfied to thereby enable a transmission from the antenna 119C tothe SAW device 158 and a modified signal to be provided from the SAWdevice 158 to the antenna 119C for transmission to the interrogator.

For example, if sensor 156 is a pressure sensor and SAW assembly isbeing used to monitor tire pressure, then when the pressure is below athreshold as detected by sensor 156, switch 129D is closed and therebyallows the SAW device 158 to provide a modified signal. Sensor 156should ideally be a sensor that does not require power (or requiresminimal power) and can continually monitor the property, for example, apressure sensing diaphragm could be used to and positioned relative tothe switch 129D so that when the pressure is below a threshold, thediaphragm moves and causes closure of the switch 129D. Indeed, theswitch 129D could even be attached to such a pressure sensing diaphragm.In this case, when the pressure is at or above the threshold, thepressure sensing diaphragm does not close switch 129D thereby conservingpower. Switch 129D would therefore be in an open position whenever thepressure was at or above the design threshold. Instead of a fixedthreshold, a variable threshold can be used based on any number offactors. Also, a temperature sensor could be used to close a switch iftemperature is being monitored, e.g., a diaphragm which expands withtemperature could be attached to the switch 129D or another thermal ortemperature switch used in the circuit. Any other type of sensor whichchanges its state or condition and can cause closure of a switch basedon a predetermined threshold, or switch which is activated based on asensed property of the tire, could also be used in the invention.

The minimal transmission from the SAW device 158 is necessary inparticular in a case where only one tire has a low pressure. One reasonfor this is because it is difficult to separate transmissions from morethan one tire when operating in the passive mode.

Any of the disclosed applications can be interrogated by the centralinterrogator of this invention and can either be powered or operatedpowerlessly as described in general above. Block diagrams of threeinterrogators suitable for use in this invention are illustrated inFIGS. 19A-19C of the '834 application. FIG. 19A illustrates a superheterodyne circuit and FIG. 19B illustrates a dual super heterodynecircuit. FIG. 19C operates as follows. During the burst time twofrequencies, F1 and F1+F2, are sent by the transmitter after beinggenerated by mixing using oscillator Osc. The two frequencies are neededby the SAW transducer where they are mixed yielding F2 which ismodulated by the SAW and contains the information. Frequency (F1+F2) issent only during the burst time while frequency F1 remains on until thesignal F2 returns from the SAW. This signal is used for mixing. Thesignal returned from the SAW transducer to the interrogator is F1+F2where F2 has been modulated by the SAW transducer. It is expected thatthe mixing operations will result in about 12 db loss in signalstrength.

As discussed elsewhere herein, the particular tire that is sending asignal can be determined if multiple antennas, such as three, eachreceive the signal. For a 500 MHz signal, for example, the wave lengthis about 60 cm. If the distance from a tire transmitter to each of threeantennas is on the order of one meter, then the relative distance fromeach antenna to the transmitter can be determined to within a fewcentimeters and thus the location of the transmitter can be found bytriangulation. If that location is not a possible location for a tiretransmitter, then the data can be ignored thus solving the problem of atransmitter from an adjacent vehicle being read by the wrong vehicleinterrogator. This will be discussed below with regard to solving theproblem of a truck having 18 tires that all need to be monitored. Notealso, each antenna can have associated with it some simple circuitrythat permits it to receive a signal, amplify it, change its frequencyand retransmit it either through a wire of through the air to theinterrogator thus eliminating the need for long and expensive coaxcables.

U.S. Pat. No. 6,622,567 describes a peak strain RFID technology baseddevice with the novelty being the use of a mechanical device thatrecords the peak strain experienced by the device. Like the system ofthe invention herein, the system does not require a battery and receivesits power from the RFID circuit. The invention described herein includesuse of RFID-based sensors either in a peak strain mode or in a preferredcontinuous strain mode. This invention is not limited to measuringstrain as SAW and RFID based sensors can be used for measuring manyother parameters including chemical vapor concentration, temperature,acceleration, angular velocity etc.

One aspect of at least one of the inventions disclosed herein is the useof an interrogator to wirelessly interrogate multiple sensing devicesthereby reducing the cost of the system since such sensors are ingeneral inexpensive compared to the interrogator. The sensing devicesare preferably based on SAW and/or RFID technologies although othertechnologies are applicable.

Antenna Considerations

Antennas are a very important aspect to SAW and RFID wireless devicessuch as can be used in tire monitors, seat monitors, weight sensors,child seat monitors, fluid level sensors and similar devices or sensorswhich monitor, detect, measure, determine or derive physical propertiesor characteristics of a component in or on the vehicle or of an areanear the vehicle. In many cases, the location of a SAW or RFID deviceneeds to be determined such as when a device is used to locate theposition of a movable item in or on a vehicle such as a seat. In othercases, the particular device from a plurality of similar devices, suchas a tire pressure and/or temperature monitor that is reporting, needsto be identified. Thus, a combination of antennas can be used and thetime or arrival, angle of arrival, multipath signature or similar methodused to identify the reporting device. One preferred method is derivedfrom the theory of smart antennas whereby the signals from multipleantennas are combined to improve the signal-to-noise ratio of theincoming or outgoing signal in the presence of multipath effects, forexample.

Additionally, since the signal level from a SAW or RFID device isfrequently low, various techniques can be used to improve thesignal-to-noise ratio as described below. Finally, at the frequenciesfrequently used such as 433 MHz, the antennas can become large andmethods are needed to reduce their size. These and other antennaconsiderations that can be used to improve the operation of SAW, RFIDand similar wireless devices are described below.

Tire Information Determination

One method of maintaining a single central antenna assembly whileinterrogating all four tires on a conventional automobile, isillustrated in FIGS. 17 and 18. The same technique may be used in theinvention when interrogating multiple components, RFID devices orRFID-equipped objects as disclosed herein.

An additional antenna can be located near the spare tire, which is notshown. It should be noted that the system described below is equallyapplicable for vehicles with more than four tires such as trucks.

A vehicle body is illustrated as 620 having four tires 621 and acentrally mounted four element, switchable directional antenna array622. The four beams are shown schematically as 623 with an inactivatedbeam as 624 and the activated beam as 625. The road surface 626 supportsthe vehicle. An electronic control circuit, not shown, which may resideinside the antenna array housing 622 or elsewhere, alternately switcheseach of the four antennas of the array 622 which then sequentially, orin some other pattern, send RF signals to each of the four tires 621 andwait for the response from the RFID, SAW or similar tire pressure,temperature, ID, acceleration and/or other property monitor arranged inconnection with or associated with the tire 621. This represents a timedomain multiple access system.

The interrogator makes sequential interrogation of wheels as follows:

Stage 1. Interrogator radiates 8 RF pulses via the first RF portdirected to the 1st wheel.

-   -   Pulse duration is about 0.8 μs.    -   Pulse repetition period is about 40 μs.    -   Pulse amplitude is about 8 V (peak to peak)    -   Carrier frequency is about 426.00 MHz.    -   (Between adjacent pulses, the receiver opens its input and        receives four-pulses echoes from the transponder located in the        first wheel).    -   Then, during a time of about 8 ms, the internal micro controller        processes and stores received data.    -   Total duration of this stage is 32 μs+8 ms=8.032 ms.

Stage 2,3,4. Interrogator repeats operations as on stage 1 for 2^(nd),3^(rd) and 4^(th) wheel sequentially via appropriate RF ports.

Stage 5. Interrogator stops radiating RF pulses and transfers datastored during stages 1-4 to the external PC for final processing anddisplaying. Then it returns to stage 1. The time interval for datatransfer equals about 35 ms.

Some notes relative to FCC Regulations:

The total duration of interrogation cycle of four wheels is

8.032 ms*4+35 ms=67.12 ms.

During this time, interrogator radiates 8*4=32 pulses, each of 0.8 μsduration.

Thus, average period of pulse repetition is

67.12 ms/32=2.09 ms=2090 μs

Assuming that duration of the interrogation pulse is 0.8 μs asmentioned, an average repetition rate is obtained

0.8 μs/2090 μs=0.38*10⁻³

Finally, the radiated pulse power is

Pp=(4 V)²/(2*50 Ohm)=0.16 W

and the average radiated power is

Pave=0.16*0.38*10⁻³=0.42*10⁻³ W, or 0.42 mW

In another application, the antennas of the array 622 transmit the RFsignals simultaneously and space the returns through the use of a delayline in the circuitry from each antenna so that each return is spaced intime in a known manner without requiring that the antennas be switched.Another method is to offset the antenna array, as illustrated in FIG.20, so that the returns naturally are spaced in time due to thedifferent distances from the tires 621 to the antennas of the array 622.In this case, each signal will return with a different phase and can beseparated by this difference in phase using methods known to those inthe art.

In another application, not shown, two wide angle antennas can be usedsuch that each receives any four signals but each antenna receives eachsignal at a slightly different time and different amplitude permittingeach signal to be separated by looking at the return from both antennassince, each signal will be received differently based on its angle ofarrival.

Additionally, each SAW or RFID device can be designed to operate on aslightly different frequency and the antennas of the array 622 can bedesigned to send a chirp signal and the returned signals will then beseparated in frequency, permitting the four signals to be separated.Alternately, the four antennas of the array 622 can each transmit anidentification signal to permit separation. This identification can be anumerical number or the length of the SAW substrate, for example, can berandom so that each property monitor has a slightly different delaybuilt in which permits signal separation. The identification number canbe easily achieved in RFID systems and, with some difficulty and addedexpense, in SAW systems. Other methods of separating the signals fromeach of the tires 621 will now be apparent to those skilled in the art.One preferred method in particular will be discussed below and makes useof an RFID switch.

There are two parameters of SAW system, which has led to the choice of afour echo pulse system:

-   -   ITU frequency rules require that the radiated spectrum width be        reduced to: Δφ≦1.75 MHz (in ISM band, F=433.92 MHz);    -   The range of temperature measurement should be from −40 F up to        +260 F.

Therefore, burst (request) pulse duration should be not less than 0.6microseconds.

τ_(bur.)=1/Δφ≧0.6 μs

This burst pulse travels to a SAW sensor and then it is returned by theSAW to the interrogator. The sensor's antenna, interdigital transducer(IDT), reflector and the interrogator are subsystems with a restrictedfrequency pass band. Therefore, an efficient pass band of all thesubsystems H(f)_(Σ) will be defined as product of the partial frequencycharacteristic of all components:

H(f)_(Σ) =H(f)₁ *H(f)₂ * . . . H(f)i

On the other hand, the frequency H(φ)_(Σ) and a time I(τ)_(Σ) responseof any system are interlinked to each other by Fourier's transform.Therefore, the shape and duration (τ_(echo puls)) an echo signal oninput to the quadrature demodulator will differ from an interrogationpulse.

In other words, duration an echo signal on input to the quadraturedemodulator is defined as mathematical convolution of a burst signalτ_(bur.) and the total impulse response of the system I(τ)_(Σ).

τ_(echo)=τ_(bur.){circle around (x)}I(τ)_(Σ)

The task is to determine maximum pulse duration on input to thequadrature demodulator τ_(echo) under a burst pulse duration τ_(bur.) of0.6 microseconds. It is necessary to consider in time all echo signals.In addition, it is necessary to take into account the following:

-   -   each subsequent echo signal should not begin earlier than the        completion of the previous echo pulse. Otherwise, the signals        will interfere with each other, and measurement will not be        correct;    -   for normal operation of available microcircuits, it is necessary        that the signal has a flat apex with a duration not less than        0.25 microseconds (τ_(meg)=t3−t2). The signal's phase will be        constant only on this segment;    -   the total sensor's pass band (considering double transit IDT and        its antenna as a reflector) constitutes 10 MHz;    -   the total pass band of the interrogator constitutes no more than        4 MHz.

Conducting the corresponding calculations yields the determination thatduration of impulse front (t2−t1=t4−t3) constitutes about 0.35microseconds. Therefore, total duration of one echo pulse is not lessthan:

τ_(echo.)=(t2−t1)+τ_(meg.)+(t4−t3)=0.35+0.25+0.35=0.95 μs

Hence, the arrival time of each following echo pulse should be notearlier than 1.0 microsecond. This conclusion is very important.

In Appendix 1 of the '139 application, it is shown that for correcttemperature measuring in the required band it is necessary to meet thefollowing conditions:

(T2−T1)=1/(72*10−6 1/° K*(125° C.−(−40° C.))*434.92*106)=194 ns

This condition is outrageous. If to execute ITU frequency rules, theband of correct temperature measuring will be reduced five times:

(125° C.−(−40° C.)*194 ns)/1000 ns=32° C.=58° F.

This is the main reason that it is necessary to add the fourth echopulse in a sensor. The principle purpose of the fourth echo pulse is tomake the temperature measurement unambiguous in a wide interval oftemperatures when a longer interrogation pulse is used (the respectivetime intervals between the sensor's echo pulses are also longer). Amathematical model of the processing of a four-pulse echo that explainsthese statements is presented in Appendix 3 of the '139 application.

The duration of the interrogation pulse and the time positions of thefour pulses are calculated as:

T1>4*τ_(echo)=4.00 μs

T2=T1+τ_(echo)=5.00 μs

T3=T2+τ_(echo)=6.00 μs

T4=T3+τ_(echo)+0.08 μs=7.08 μs

The sensor's design with four pulses is exhibited in FIGS. 25 and 26 ofthe '834 application.

-   -   τ_(bur) 0.60 μs    -   T1 4.00 μs    -   T2 5.00 μs    -   T3 6.00 μs    -   T4 7.08 μs

The reason that such a design was selected is that this design providesthree important conditions:

1. It has the minimum RF signal propagation loss. Both SAW waves use formeasuring (which are propagated to the left and to the right from IDT).

2. All parasitic echo signals (signals of multiple transits) areeliminated after the fourth pulse. For example, the pulse is excited bythe IDT, then it is reflected from a reflector No 1 and returns to theIDT. The pulse for the second time is re-emitted and it passes thesecond time on the same trajectory. The total time delay will be 8.0microseconds in this case.

3. It has the minimum length.

Although the discussion herein concerns the determination of tireinformation, the same system can be used to determine the location ofseats, the location of child seats when equipped with sensors,information about the presence of object or chemicals in vehicularcompartments and the like.

Smart Antennas

Some of the shortcomings in today's wireless products can be overcome byusing smart antenna technology. A smart antenna is a multi-elementantenna that significantly improves reception by intelligently combiningthe signals received at each antenna element and adjusting the antennacharacteristics to optimize performance as the transmitter or receivermoves and the environment changes.

Smart antennas can suppress interfering signals, combat signal fadingand increase signal range thereby increasing the performance andcapacity of wireless systems.

A method of separating signals from multiple tires, for example, is touse a smart antenna such as that manufactured by Motia. This particularMotia device is designed to operate at 433 MHz and to mitigate multipathsignals at that frequency. The signals returning to the antennas fromtires, for example, contain some multipath effects that, especially ifthe antennas are offset somewhat from the vehicle center, are differentfor each wheel. Since the adaptive formula will differ for each wheel,the signals can be separated (see “enhancing 802.11 WLANs through SmartAntennas”, January 2004 available at motia.com). The following is takenfrom that paper.

“Antenna arrays can provide gain, combat multipath fading, and suppressinterfering signals, thereby increasing both the performance andcapacity of wireless systems. Smart antennas have been implemented in awide variety of wireless systems, where they have been demonstrated toprovide a large performance improvement. However, the various types ofspatial processing techniques have different advantages anddisadvantages in each type of system.”

“This strategy permits the seamless integration of smart antennatechnology with today's legacy WLAN chipset architecture. Since the802.11 system uses time division duplexing (the same frequency is usedfor transmit and receive), smart antennas can be used for both transmitand receive, providing a gain on both uplink and downlink, using smartantennas on either the client or access point alone. Results show a 13dB gain with a four element smart antenna over a single antenna systemwith the smart antenna on one side only, and an 18 dB gain with thesmart antenna on both the client and access point. Thus, this“plug-and-play” adaptive array technology can provide greater range,average data rate increases per user, and better overall coverage.

“In the multibeam or phased array antenna, a beamformer forms severalnarrow beams, and a beam selector chooses the beam for reception thathas the largest signal power. In the adaptive array, the signal isreceived by several antenna elements, each with similar antennapatterns, and the received signals are weighted and combined to form theoutput signal. The multibeam antenna is simpler to implement as thebeamformer is fixed, with the beam selection only needed every fewseconds for user movement, while the adaptive array must calculate thecomplex beamforming weights at least an order of magnitude faster thanthe fading rate, which can be several Hertz for pedestrian users.”

“Finally, there is pattern diversity, the use of antenna elements withdifferent patterns. The combination of these types of diversity permitsthe use of a large number of antennas even in a small form factor, suchas a PCMCIA card or handset, with near ideal performance.”

Through its adaptive beamforming technology, Motia has developedcost-effective smart antenna appliques that vastly improve wirelessperformance in a wide variety of wireless applications including Wi-Fithat can be incorporated into wireless systems without majormodifications to existing products. Although the Motia chipset has beenapplied to several communication applications, it has yet to be appliedto all of the monitoring applications as disclosed in the currentassignee's patents and pending patent applications, and in particularvehicular monitoring applications such as tire monitoring.

The smart antenna works by determining a set of factors or weights thatare used to operate on the magnitude and/or phase of the signals fromeach antenna before the signals are combined. However, since thegeometry of a vehicle tire relative to the centralized antenna arraydoes not change much as the tire rotates, but is different for eachwheel, the weights themselves contain the information as to which tiresignal is being received. In fact, the weights can be chosen to optimizesignal transmission from a particular tire thus providing a method ofselectively interrogating each tire at the maximum antenna gain.

Distributed Load Monopole

Antenna developments in the physics department at the University ofRhode Island have resulted in a new antenna technology. The antennasdeveloped called DLM's (Distributed loaded monopole) are smallefficient, wide bandwidth antennas. The simple design exhibits 50-ohmimpedance and is easy to implement. They require only a direct feed froma coax cable and require no elaborate matching networks.

The prime advantage to this technology is a substantial reduction of thesize of an antenna. Typically, the DLM antenna is about ⅓ the size of anormal dipole with only minor loss in efficiency. This is especiallyimportant for vehicle applications where space is always at a premium.Such antennas can be used for a variety of vehicle radar andcommunication applications as well for the monitoring of RFID, SAW andsimilar devices on a vehicle and especially for tire pressure,temperature, and/or acceleration monitoring as well as other monitoringpurposes. Such applications have not previously been disclosed.

Although the DLM is being applied to several communication applications,it has yet to be applied to all of the monitoring applications asdisclosed in the current assignee's patents and pending patentapplications. The antenna gain that results and the ability to packseveral antennas into a small package are attractive features of thistechnology.

Plasma Antenna

The following disclosure was taken from “Markland Technologies—GasPlasma”.

“Plasma antenna technology employs ionized gas enclosed in a tube (orother enclosure) as the conducting element of an antenna. This is afundamental change from traditional antenna design that generallyemploys solid metal wires as the conducting element. Ionized gas is anefficient conducting element with a number of important advantages.Since the gas is ionized only for the time of transmission or reception,“ringing” and associated effects of solid wire antenna design areeliminated. The design allows for extremely short pulses, important tomany forms of digital communication and radars. The design furtherprovides the opportunity to construct an antenna that can be compact anddynamically reconfigured for frequency, direction, bandwidth, gain andbeamwidth. Plasma antenna technology will enable antennas to be designedthat are efficient, low in weight and smaller in size than traditionalsolid wire antennas.”

“When gas is electrically charged, or ionized to a plasma state itbecomes conductive, allowing radio frequency (RF) signals to betransmitted or received. We employ ionized gas enclosed in a tube as theconducting element of an antenna. When the gas is not ionized, theantenna element ceases to exist. This is a fundamental change fromtraditional antenna design that generally employs solid metal wires asthe conducting element. We believe our plasma antenna offers numerousadvantages including stealth for military applications and higherdigital performance in commercial applications. We also believe ourtechnology can compete in many metal antenna applications.”

“Initial studies have concluded that a plasma antenna's performance isequal to a copper wire antenna in every respect. Plasma antennas can beused for any transmission and/or modulation technique: continuous wave(CW), phase modulation, impulse, AM, FM, chirp, spread spectrum or otherdigital techniques. And the plasma antenna can be used over a largefrequency range up to 20 GHz and employ a wide variety of gases (forexample neon, argon, helium, krypton, mercury vapor and xenon). The sameis true as to its value as a receive antenna.”

“Plasma antenna technology has the following additional attributes:

-   -   No antenna ringing provides an improved signal to noise ratio        and reduces multipath signal distortion.    -   Reduced radar cross section provides stealth due to the        non-metallic elements.    -   Changes in the ion density can result in instantaneous changes        in bandwidth over wide dynamic ranges.    -   After the gas is ionized, the plasma antenna has virtually no        noise floor.    -   While in operation, a plasma antenna with a low ionization level        can be decoupled from an adjacent high-frequency transmitter.    -   A circular scan can be performed electronically with no moving        parts at a higher speed than traditional mechanical antenna        structures.    -   It has been mathematically illustrated that by selecting the        gases and changing ion density that the electrical aperture (or        apparent footprint) of a plasma antenna can be made to perform        on par with a metal counterpart having a larger physical size.    -   Our plasma antenna can transmit and receive from the same        aperture provided the frequencies are widely separated.    -   Plasma resonance, impedance and electron charge density are all        dynamically reconfigurable. Ionized gas antenna elements can be        constructed and configured into an array that is dynamically        reconfigurable for frequency, beamwidth, power, gain,        polarization and directionality—on the fly.    -   A single dynamic antenna structure can use time multiplexing so        that many RF subsystems can share one antenna resource reducing        the number and size of antenna structures.”

Several of the characteristics discussed above are of particularusefulness for several of the inventions herein including the absence ofringing, the ability to turn the antenna off after transmission and thenimmediately back on for reception, the ability to send very shortpulses, the ability to alter the directionality of the antenna and tosweep thereby allowing one antenna to service multiple devices such astires and to know which tire is responding. Additional advantagesinclude, smaller size, the ability to work with chirp, spread spectrumand other digital technologies, improved signal to noise ratio, widedynamic range, circular scanning without moving parts, and antennasharing over differing frequencies, among others.

Some of the applications disclosed herein can use ultra widebandtransceivers. UWB transceivers radiate most of the energy with itsfrequency centered on the physical length of the antenna. With the UWBconnected to a plasma antenna, the center frequency of the UWBtransceiver could be hopped or swept simultaneously.

A plasma antenna can solve the problem of multiple antennas by changingits electrical characteristic to match the function required—Time domainmultiplexed. It can be used for high-gain antennas such as phase array,parabolic focus steering, log periodic, yogi, patch quadrafiler, etc.One antenna can be used for GPS, ad-hoc (such as car-to-car)communication, collision avoidance, back up sensing, cruse control,radar, toll identification and data communications.

Although the plasma antennas are being applied to several communicationapplications, they have yet to be applied to the monitoring applicationsas disclosed herein. The many advantages that result and the ability topack several antenna functions into a small package are attractivefeatures of this technology. Patents and applications that discussplasma antennas include: U.S. Pat. No. 6,710,746 and U.S. Pat. App. PubNos. 20030160742 and 20040130497.

Dielectric Antenna

A great deal of work is underway to make antennas from dielectricmaterials. In one case, the electric field that impinges on thedielectric is used to modulate a transverse electric light beam. Inanother case, the reduction of the speed of electro magnetic waves dueto the dielectric constant is used to reduce the size of the antenna. Itcan be expected that developments in this area will affect the antennasused in cell phones as well as in RFID and SAW-based communicationdevices in the future. Thus, dielectric antennas can be advantageouslyused with some of the inventions disclosed herein.

Nanotube Antenna

Antennas made from carbon nanotubes are beginning to show promise ofincreasing the sensitivity of antennas and thus increasing the range forcommunication devices based on RFID, SAW or similar devices where thesignal strength frequently limits the range of such devices. The use ofthese antennas is therefore contemplated herein for use in tire monitorsand the other applications disclosed herein.

Combinations of the above antenna designs in many cases can benefit fromthe advantages of each type to add further improvements to the field.Thus the inventions herein are not limited to any one of the aboveconcepts nor is it limited to their use alone. Where feasible, allcombinations are contemplated herein.

Antenna Summary

A general system for obtaining information about a vehicle or acomponent thereof or therein is illustrated in FIG. 19 and includesmultiple sensors 627 which may be arranged at specific locations on thevehicle, on specific components of the vehicle, on objects temporarilyplaced in the vehicle such as child seats, or on or in any other objectin or on the vehicle or in its vicinity about which information isdesired. The sensors 627 may be SAW or RFID sensors or other sensorswhich generate a return signal upon the detection of a transmitted radiofrequency signal. A single multi-element antenna array 622 is mounted onthe vehicle, in either a central location as shown in FIG. 17 or in anoffset location as shown in FIG. 20, to provide the radio frequencysignals which cause the sensors 627 to generate the return signals. Ineither case, the antenna array 622 is mounted between the sides of thevehicle and includes at least one antenna element directed to each sidein order that the antenna array 622 is able to communicate with sensors627 on both sides of the vehicle, i.e., the right and left sides of thevehicle. Thus, the single antenna array 622 mounted between the sides ofthe vehicle is able to communicate with sensors throughout the vehicle,including on both sides of the vehicle.

A control system 628 is coupled to the antenna array 622 and controlsthe antennas in the array 622 to be operative as necessary to enablereception of return signals from the sensors 627. There are several waysfor the control system 628 to control the array 622, including to causethe antennas to be alternately switched on in order to sequentiallytransmit the RF signals therefrom and receive the return signals fromthe sensors 627 and to cause the antennas to transmit the RF signalssimultaneously and space the return signals from the sensors 627 via adelay line in circuitry from each antennas such that each return signalis spaced in time in a known manner without requiring switching of theantennas. The control system can also be used to control a smart antennaarray.

The control system 628 also processes the return signals to provideinformation about the vehicle or the component. The processing of thereturn signals can be any known processing including the use of patternrecognition techniques, neural networks, fuzzy systems and the like.

The antenna array 622 and control system 628 can be housed in a commonantenna array housing 630.

Once the information about the vehicle or the component is known, it isdirected to a display/telematics/adjustment unit 629 where theinformation can be displayed on a display 629 to the driver, sent to aremote location for analysis via a telematics unit 629 and/or used tocontrol or adjust a component on, in or near the vehicle. Althoughseveral of the figures illustrate applications of these technologies totire monitoring, it is intended that the principles and devicesdisclosed can be applied to the monitoring of a wide variety ofcomponents on and off a vehicle.

In summary, the use of devices capable of reading or scanning RFIDdevices when situated in compartments or spaces defined by vehicles orother mobile assets provides significant advantages. Among other things,it allows for the determination of the identification and location ofthe RFID devices and thus objects equipped with such RFID devices, andwith a communications or telematics unit coupled to the interrogator, itallows for communication of that information off of the vehicle, i.e.,to one or more remote sites. The overall system identifies the RFIDdevice if it generates a unique identification code, which is usuallythe case, and thus can generate a transmission to the remote sitecontaining an identification of an object in a space of a mobile asset.

With the foregoing system, it is possible at the remote site to locateand monitor the RFID-equipped object.

Alternative or in addition to the communication to a remote site, theinterrogator could also transmit or otherwise provide the signal with anidentification of the object to another system on the vehicle itself. Inthis manner, someone looking for an RFID-equipped object in a spacecould easily determine its location, such as a package delivery driverlooking for a specific package in a truck or an airline worker lookingfor a specific passenger's luggage.

Referring now to FIGS. 21-24, additional aspects of the monitoring ofinterior contents of a shipping container, trailer, boat, shed, etc.will now be described. Generally, these contents can be removed from thevehicle and thus are usually not directly attached to a frame of thevehicle which defines the object-containing interior. Such a frame mayhave the form of a truck, a truck trailer, a shipping container, a boat,an airplane or another vehicle.

Commercial systems are now available from companies such as Skybitz Inc.45365 Vintage Park Plaza, Suite 210, Dulles, Va. 20166-6700, which willmonitor the location of an asset anywhere on the surface of the earth.Each monitored asset contains a low cost GPS receiver and a satellitecommunication system. The system can be installed onto a truck, trailer,container, or other asset and it well periodically communicate with alow earth orbit (LEO) or a geostationary satellite providing thesatellite with its location as determined by the GPS receiver or asimilar system such as the Skybitz Global Locating System (GLS). Theentire system operates off of a battery, for example, and if the systemtransmits information to the satellite once per day, the battery canlast many years before requiring replacement. Thus, the system canmonitor the location of a trailer, for example, once per day, which issufficient if trailer is stationary. The interrogation rate can beautomatically increased if the trailer begins moving. Such a system canlast for 2 to 10 years without requiring maintenance depending ondesign, usage and the environment. Even longer periods are possible ifpower is periodically or occasionally available to recharge the batterysuch as by vibration energy harvesting, solar cells, capacitivecoupling, inductive coupling, RF or vehicle power. In some cases, anultracapacitor as discussed above can be used in place of a battery.

The SkyBitz system by itself only provides information as to thelocation of a container and not information about its contents,environment, and/or other properties. At least one of the inventionsdisclosed herein disclosed here is intended to provide this additionalinformation, which can be coded typically into a few bytes and sent tothe satellite along with the container location information andidentification. First, consider monitoring of the interior contents of acontainer. From here on, the terms “shipping container” or “container”will be used as a generic cargo holder and will include all cargoholders including standard and non-standard containers, boats, trucks,trailers, sheds, warehouses, storage facilities, tanks, pipelines,buildings or any other such object that has space and can hold cargo.Most of these “containers” are also vehicles as defined above.

Consider now a standard shipping container that is used for shippingcargo by boat, trailer, or railroad, such cargo being usually inanimate,i.e., not alive. Such containers are nominally 8′w×8′h×20′ or 40′ longoutside dimensions, however, a container 48′ in length is also sometimesused. The inside dimensions are frequently around 4″ less than theoutside dimensions. In a simple interior container monitoring system,one or more ultrasonic transducers can be mounted on an interior part ofthe container adjacent the container's ceiling in a protective housing.Periodically, the ultrasonic transducers can emit a few cycles ofultrasound and receive reflected echoes of this ultrasound from wallsand contents of the trailer. In some cases, especially for longcontainers, one or more transducers, typically at one end of thecontainer, can send to one or more transducers located at, for example,the opposite end. Usually, however, the transmitters and receivers arelocated near each other. Due to the long distance that the ultrasoundwaves must travel especially in the 48 foot container, it is frequentlydesirable to repeat the send and receive sequence several times and toadd or average the results. This has the effect of improving the signalto noise ratio. Note that the system disclosed herein and in the parentpatents and applications is able to achieve such long sensing distancesdue to the principles disclosed herein. Competitive systems that are nowbeginning to enter the market have much shorter sensing distances andthus a key invention herein is the ability to achieve sensing distancesin excess of 20 feet.

Note that in many cases several transducers are used for monitoring thevehicle such as a container that typically point in slightly differentdirections. This need not be the case and a movable mounting is alsocontemplated where the motion is accomplished by any convenient methodsuch as a magnet, motor, etc.

Referring to FIG. 21, a container 480 is shown including an interiorsensor system 481 arranged to obtain information about contents in theinterior of the container 480. The interior sensor system includes awave transmitter 482 mounted at one end of the container 480 and whichoperatively transmits waves into the interior of the container 480 and awave receiver 483 mounted adjacent the wave transmitter 482 and whichoperatively receives waves from the interior of the container 480. Asshown, the transmitter 482 and receiver 483 are adjacent one another butsuch a positioning is not intended to limit the invention. Thetransmitter 482 and receiver 483 can be formed as a single transducer ormay be spaced apart from one another. Multiple pairs oftransmitter/receivers can also be provided, for example transmitter 482′and receiver 483′ are located at an opposite end of the container 480proximate the doors 484.

The interior sensor system 481 includes a processor coupled to thereceiver 483, and optionally the transmitter 482, and which is residenton the container 480, for example, in the housing of the receiver 483 orin the housing of a communication system 485. The processor isprogrammed to compare waves received by each receiver 483, 483′ atdifferent times and analyze either the received waves individually orthe received waves in comparison to or in relation to other receivedwaves for the purpose of providing information about the contents in theinterior of the container 480. The processor can employ patternrecognition techniques and as discussed more fully below, be designed tocompensate for thermal gradients in the interior of the container 480.Information about the contents of the container 480 may comprise thepresence or motion of objects in the interior. The processor may beassociated with a memory unit which can store data on the location ofthe container 480 and the analysis of the data from the interior sensorsystem 481.

The container 480 also includes a location determining system 486 whichmonitors the location of the container 480. To this end, the locationdetermining system can be any asset locator in the prior art, whichtypically include a GPS receiver, transmitter and appropriate electronichardware and software to enable the position of the container 480 to bedetermined using GPS technology or other satellite or ground-basedtechnology including those using the cell phone system or similarlocation based systems.

The communication system 485 is coupled to both the interior sensorsystem 481 and the location determining system 486 and transmits theinformation about the contents in the interior of the container 480(obtained from the interior sensor system 481) and the location of thecontainer 480 (obtained from the location determining system 486). Thistransmission may be to a remote facility wherein the information aboutthe container 480 is stored, processed, counted, reviewed and/ormonitored and/or retransmitted to another location, perhaps by way ofthe Internet.

The container 480 also includes a door status sensor 487 arranged todetect when one or both doors 484 is/are opened or closed after havingbeen opened. The door status sensor 487 may be an ultrasonic sensorwhich is positioned a fixed distance from the doors 484 and registerschanges in the position of the doors 484. Alternately, other door statussystems can be used such as those based on switches, magnetic sensors,light sensors or other technologies. The door status sensor 487 can beprogrammed to associate an increase in the distance between the sensor487 and each of the doors 484 and a subsequent decrease in the distancebetween the sensor 487 and that door 484 as an opening and subsequentclosing of that door 484. In the alternative, a latching device can beprovided to detect latching of each door 484 upon its closure. The doorstatus sensor 487 is coupled to the interior sensor system 481, or atleast to the transmitters 482,482′ so that the transmitters 482,482′ canbe designed to transmit waves into the interior of the container 480only when the door status sensor 487 detects, for example, when at leastone door 484 is closed after having been opened. For other purposes, theultrasonic sensors may be activated on opening of the door(s) in orderto monitor the movement of objects into or out of the container, whichmight in turn be used to activate an RFID or bar code reading system orother object identification system. Thus, the interior sensor system 481may be initiated to obtain information about the contents in theinterior of the container 480 as a function of the status or movement ofthe door 484.

When the ultrasonic transducers are first installed into the container480 and the doors 484 closed, an initial pulse transmission can beinitiated and the received signal stored to provide a vector of datathat is representative of an empty container. To initiate the pulsetransmission, an initiation device or function is provided in theinterior sensor system 481, e.g., the door status sensor 487. At asubsequent time when contents have been added to the container (aspossibly reflected in the opening and closing of the doors 484 asdetected by the door status sensor 487), the ultrasonic transducers canbe commanded to again issue a few cycles of ultrasound and record thereflections. If the second pattern is subtracted from the first pattern,or otherwise compared, in the processor the existence of additionalcontents in the container 480 will cause the signal to change, whichthus causes the differential signal to change and the added contentsdetected. Vector as used herein with ultrasonic systems is a lineararray of data values obtained by rectifying, taking the envelope anddigitizing the returned signal as received by the transducer or otherdigital representation comprising at least a part of the returnedsignal.

Another use of the door status sensor 487 is to cause storage of dataabout the contents in the container 480 as a function of opening andclosing of the doors 484. Thus, the memory unit would store dataindicating each time the doors 484 are opened and closed and thecontents of the container 480 before and after each opening and closing.This will provide information about the loading and unloading of thecontents form the container 480. Data about the contents of thecontainer 480 may be obtained in any of the ways described herein,including using sensor systems 491 placed on each object in the interiorof the container 480.

When a container 480 is exposed to sunlight on its exterior top, astable thermal gradient can occur inside the container 480 where the topof the container 480 near the ceiling is at a significantly highertemperature than the bottom of the container 480. This thermal gradientchanges the density of the gas inside the container causing it to act asa lens to ultrasound that diffracts or bends the ultrasonic waves andcan significantly affect the signals sensed by the receiver portions483,483′ of the transducers. Thus, the vector of sensed data when thecontainer is at a single uniform temperature will look significantlydifferent from the vector of sensed data acquired within the samecontainer when thermal gradients are present.

It is even possible for currents of heated air to occur within acontainer 480 if a side of the container is exposed to sunlight. Sincethese thermal gradients can substantially affect the vector, the systemmust be examined under a large variety of different thermalenvironments. This generally requires that the electronics be designedto mask somewhat the effects of the thermal gradients on the magnitudeof the sensed waves while maintaining the positions of these waves intime. This can be accomplished as described in above-referenced patentsand patent applications through the use, for example, of a logarithmiccompression circuit. There are other methods of minimizing the effect onthe reflected wave magnitudes that will accomplish substantially thesame result some of which are disclosed elsewhere herein.

When the complicating aspects of thermal gradients are taken intoaccount, in many cases a great deal of data must be taken with a largenumber of different occupancy situations to create a database of perhaps10,000 to one million vectors each representing the different occupancystate of the container in a variety of thermal environments. This datacan then be used to train a pattern recognition system such as a neuralnetwork, modular or combination neural network, cellular neural network,support vector machine, fuzzy logic system, Kalman filter system, sensorfusion system, data fusion system or other classification system. Sinceall containers of the type transported by ships, for example, are ofstandard sizes, only a few of these training exercises need to beconducted, typically one for each different geometry container. Theprocess of adapting an ultrasonic occupancy monitoring system to acontainer or other space is described for automobile interior monitoringin above-referenced patents and patent applications, and therefore thisprocess is not repeated here.

Other kinds of interior monitoring systems can be used to determine andcharacterize the contents of a space such as a container. One exampleuses a scanner and photocell 488, as in a laser radar system, and can bemounted near the floor of the container 480 and operated to scan thespace above the floor in a plane located, for example, 10 cm above thefloor. Since the distance to a reflecting wall of the container 480 canbe determined and recorded for each angular position of the scanner, thedistance to any occupying item will show up as a reflection from anobject closer to the scanner and therefore a shadow graph of thecontents of the container 10 cm above the floor can be obtained and usedto partially categorize the contents of the container 480.Categorization of the contents of the container 480 may involve the useof pattern recognition technologies. Other locations of such a scanningsystem are possible.

In both of these examples, relatively little can be learned about thecontents of the container other than that something is present or thatthe container is empty. Frequently, this is all that is required. A moresophisticated system can make use of one or more imagers (for examplecameras) 489 mounted near the ceiling of the container, for example.Such imagers can be provided with a strobe flash and then commanded tomake an image of the trailer interior at appropriate times. The outputfrom such an imager 489 can also be analyzed by a pattern recognitionsystem such as a neural network or equivalent, to reduce the informationto a few bytes that can be sent to a central location via an LEO orgeostationary satellite, for example. As with the above ultrasonicexample, one image can be subtracted from the empty container image andif anything remains then that is a representation of the contents thathave been placed in the container. Also, various images can besubtracted to determine the changes in container contents when the doorsare opened and material is added or removed or to determine changes inposition of the contents. Various derivatives of this information can beextracted and sent by the telematics system to the appropriate locationfor monitoring or other purposes.

Each of the systems mentioned above can also be used to determinewhether there is motion of objects within the container relative to thecontainer. Motion of objects within the container 480 would be reflectedas differences between the waves received by the transducers (indicativeof differences in distances between the transducer and the objects inthe container) or images (indicative of differences between the positionof objects in the images). Such motion can also aid in imagesegmentation which in turn can aid in the object identification process.This is particularly valuable if the container is occupied by life formssuch as humans.

In the system of FIG. 21, wires (not shown) are used to connect thevarious sensors and devices. It is contemplated that all of the units inthe monitoring system can be coupled together wirelessly, using forexample the Bluetooth, WI-FI, Wibree or other protocol. See Hunn, Nick“An Introduction to Wibree”, EZURiO Ltd. Thus, any type or form ofwired, wireless or combination network can be used to connect thesensors and other parts of the monitoring arrangement together on theasset.

If an inertial device 490 is also incorporated, such as the MEMSIC dualaxis accelerometer, which provides information as to the accelerationsof the container 480, then this relative motion can be determined by theprocessor and it can be ascertained whether this relative motion iscaused by acceleration of the container 480, which may indicate loosecargo, and/or whether the motion is caused by the sensed occupying item.In latter case, a conclusion can perhaps be reached that container isoccupied by a life form such as an animal or human.

Additionally, it may be desirable to place sensors on an item of cargoitself since damage to the cargo could occur from excessiveacceleration, shock, temperature, vibration, etc. regardless of whetherthe same stimulus was experienced by the entire container. A loose itemof cargo, for example, may be impacting the monitored item of cargo anddamaging it. Thus, any of the sensors described herein, e.g., chemicalsensors, motion sensors and the like, can be placed on each item ofcargo or object and connected by wires or wirelessly to a receiving unitwhich receives data obtained by such object-mounted sensors. Dataobtained from the sensors may be communicated to a remote facility.Also, the obtaining of the data can be done periodically or triggered byany of the triggers described for obtaining data via the asset-mountedsensor systems.

Relative motion can also be sensed in some cases from outside of thecontainer through the use of accelerometers, microphones or MIR(Micropower Impulse Radar). Note that all such sensors regardless ofwhere they are placed are contemplated herein and are part of thepresent inventions.

Chemical sensors 491 based on surface acoustic wave (SAW), MEMS or othertechnology can in many cases be designed to sense the presence ofcertain vapors in the atmosphere and can do so at very low power. Aproperly designed SAW or equivalent sensing device, for example, canmeasure acceleration, angular rate, strain, temperature, pressure,carbon dioxide concentration, humidity, hydrocarbon concentration, andthe presence or concentration of many other chemicals. A separate SAW orsimilar device may be needed for each chemical species (or in some caseseach class of chemicals) where detection is desired. The devices,however, can be quite small and can be designed to use very littlepower. Such a system of SAW or equivalent devices can be used to measurethe existence of certain chemical vapors in the atmosphere of thecontainer, or the atmosphere around an object in the interior of acontainer, much like a low power electronic nose. In some cases, it canbe used to determine whether a carbon dioxide source such as a human isin the container, or in the object. Such chemical sensing devices canalso be designed, for example, to monitor for many other chemicalsincluding some narcotics, hydrocarbons, mercury vapor, and otherhazardous chemicals including some representative vapors of explosivesor some weapons of mass destruction. With additional research, SAW orsimilar devices can also be designed or augmented to sense the presenceof radioactive materials, and perhaps some biological materials such assmallpox or anthrax. In many cases, such SAW devices do not now exist,however, researchers believe that given the proper motivation that suchdevices can be created. Thus, although heretofore not appreciated, SAWor equivalent based systems can monitor a great many dangerous andhazardous materials that may be either legally or illegally occupyingspace within a container, for example. In particular, the existence ofspills or leakages from the cargo can be detected in time to perhapssave damage to other cargo either within the container or in an adjacentcontainer. Although SAW devices have in particular been described, otherlow power devices using battery or RF power can also be used wherenecessary. Note, the use of any of the afore mentioned SAW devices inconnection within or on a vehicle for any purpose other than tirepressure and temperature monitoring or torque monitoring is new andcontemplated by the inventions disclosed herein. Only a small number ofexamples are presented of the general application of the SAW, or RFID,technology to vehicles.

Other sensors that can be designed to operate under very low powerlevels include microphones 492 and light sensors 493 or sensorssensitive to other frequencies in the electromagnetic spectrum as theneed arises. The light sensors 493 could be designed to cause activationof the interior sensor system 481 when the container is being switchedfrom a dark condition (normally closed) to a light situation (when thedoor or other aperture is opened). A flashlight could also activate thelight sensor 493.

Instead of one or more batteries providing power to the interior sensorsystem 481, the communication system 485 and the location determiningsystem 486, solar power can be used. In this case, one or more solarpanels 494 are attached to the upper wall of the container 480 (see FIG.57) and electrically coupled to the various power-requiring componentsof the monitoring system. A battery can thus be eliminated. In thealternative, since the solar panel(s) 494 will not always be exposed tosunlight, a rechargeable battery can be provided which is charged by thesolar panel 494 when the solar panels are exposed to sunlight. A batterycould also be provided in the event that the solar panel 494 does notreceive sufficient light to power the components of the monitoringsystem. In a similar manner, power can temporarily be supplied by avehicle such as a tractor either by a direct connection to the tractorpower or though capacitive, inductive or RF coupling power transmissionsystems. As above an ultracapacitor can be used instead of a battery andenergy harvesting can be used if there is a source of energy such aslight or vibration in the environment.

In some cases, a container is thought to be empty when in fact it isbeing surreptitiously used for purposes beyond the desires of thecontainer owner or law enforcement authorities. The various transducersthat can be used to monitor interior of a container as described above,plus others, can also be used to allow the trailer or container owner toperiodically monitor the use of his property.

Immediately above, monitoring of the interior of the container isdescribed. If the container is idle, there may not the need tofrequently monitor the status of the container interior or exterioruntil some event happens. Thus, all monitoring systems on the containercan be placed in the sleep mode until some event such as a motion orvibration of the container takes place. Other wakeup events couldinclude the opening of the doors, the sensing of light or a change inthe interior temperature of the container above a reference level, forexample. When any of these chosen events occurs, the system can beinstructed to change the monitoring rate and to immediately transmit asignal to a satellite or another communication system, or respond to asatellite-initiated signal for some LEO-based, or geocentric systems,for example. Such an event may signal to the container owner that arobbery was in progress either of the interior contents of the containeror of the entire container. It also might signal that the contents ofthe container are in danger of being destroyed through temperature orexcessive motion or that the container is being misappropriated for someunauthorized use.

FIG. 22 shows a flowchart of the manner in which container 480 may bemonitored by personnel or a computer program at a remote facility forthe purpose of detecting unauthorized entry into the container andpossible theft of the contents of the container 480. Initially, thewakeup sensor 495 detects motion, sound, light or vibration includingmotion of the doors 484, or any other change of the condition of thecontainer 480 from a stationary or expected position. The wakeup sensor495 can be designed to provide a signal indicative of motion only aftera fixed time delay, i.e., a period of “sleep”. In this manner, thewakeup sensor would not be activated repeatedly in traffic stop and gosituations.

The wakeup sensor 495 initiates the interior sensor system 481 toperform the analysis of the contents in the interior of the container,e.g., send waves into the interior, receive waves and then process thereceived waves. If motion in the interior of the container is notdetected at 496, then the interior sensor system 481 may be designed tocontinue to monitor the interior of the container, for example, byperiodically re-sending waves into the interior of the container. Ifmotion is detected at 496, then a signal is sent at 497 to a monitoringfacility via the communication system 485 and which includes thelocation of the container 480 obtained from the location determiningsystem 486 or by the ID for a permanently fixed container or otherasset, structure or storage facility. In this manner, if the motion isdetermined to deviate from the expected handling of the container 480,appropriate law enforcement personnel can be summoned to investigate.

When it is known and expected that the container should be in motion,monitoring of this motion can still be important. An unexpectedvibration could signal the start of a failure of the chassis tire, forexample, or failure of the attachment to the chassis or the attachmentof the chassis to the tractor. Similarly, an unexpected tilt angle ofthe container may signify a dangerous situation that could lead to arollover accident and an unexpected shock could indicate an accident hasoccurred. Various sensors that can be used to monitor the motion of thecontainer include gyroscopes, accelerometers and tilt sensors. An IMU(Inertial Measurement Unit) containing for example three accelerometersand three gyroscopes can be used.

In some cases, the container or the chassis can be provided with weightsensors that measure the total weight of the cargo as well as thedistribution of weight. By monitoring changes in the weight distributionas the vehicle is traveling, an indication can result that the contentswithin the trailer are shifting which could cause damage to the cargo.An alternate method is to put weight sensors in the floor or as a mat onthe floor of the vehicle. The mat design can use the bladder principlesdescribed above for weighing b vehicle occupants using, in most cases,multiple chambers. Strain gages can also be configured to measure theweight of container contents. An alternate approach is to use inertialsensors such as accelerometers and gyroscopes to measure the motion ofthe vehicle as it travels. If the characteristics of the inputaccelerations (linear and angular) are known from a map, for example, orby measuring them on the chassis then the inertial properties of thecontainer can be determined and thus the load that the containercontains. This is an alternate method of determining the contents of acontainer. If several (usually 3) accelerometers and several (usually 3)gyroscopes are used together in a single package then this is known asan inertial measurement unit. If a source of position is also known suchas from a GPS system then the errors inherent in the IMU can becorrected using a Kalman filter.

Other container and chassis monitoring can include the attachment of atrailer to a tractor, the attachment of electrical and/or communicationconnections, and the status of the doors to the container. If the doorsare opened when this is not expected, this could be an indication of acriminal activity underway. Several types of security seals areavailable including reusable seals that indicate when the door is openor closed or if it was ever opened during transit, or single use sealsthat are destroyed during the process of opening the container.

Referring now to FIG. 3C, another application of monitoring the entireasset would be to incorporate a diagnostic module 472 into the asset.Frequently, the asset may have operating parts, e.g., if it is arefrigerated and contains a refrigeration unit 470. To this end, sensors474, e.g., temperature sensors, can be installed on the asset andmonitored using pattern recognition techniques embodied in a processorof the diagnostic module 472, as disclosed in U.S. Pat. No. 5,809,437and U.S. Pat. No. 6,175,787. As such, various sensors 474 would beplaced on the container 480 and used to determine problems with thecontainer 480 or refrigeration unit 470 which might cause it to operateabnormally, e.g., if the refrigeration unit were about to fail becauseof a refrigerant leak. Sensors 474 would indicate a higher temperaturethan expected if the refrigeration unit 470 were not operating normally.In this case, the information about the expected failure of therefrigeration unit 470 could be transmitted to a facility, via a linkbetween the diagnostic module 472 and the communications system 485, andmaintenance of the refrigeration unit could be scheduled, e.g., based onthe location of the personnel capable of fixed or replacing therefrigeration unit 470 and the location of the asset which is alsotransmitted by the communications unit 485. Instead of using sensors 474apart from the refrigeration unit 470, or other operating part whoseoperating is being diagnosed, to determine abnormal operation, it isalso possible to connect the diagnostic module 472 to the refrigerationunit 470 so that it can directly monitor the operation thereof, thisconnection being represented by a line in FIG. 3C.

It is anticipated that whatever entity is monitoring a plurality ofassets could strategically locate personnel capable of fixing orreplacing abnormally operating parts of the asset to ensure securecarriage of the goods in the asset, e.g., perishable products. Thus,when the asset provides a signal indicative of abnormal operation andits location to the remote facility, personnel at the remote facilitycould dispatch the nearest personnel to attend to the asset.

It can also be desirable to detect unauthorized entry into container,which could be by cutting with a torch, or motorized saw, grinding, orblasting through the wall, ceiling, or floor of the container. Thisevent can be detected by one or more of the following methods:

1. A light sensor which measures any part of the visible or infraredpart of the spectrum and is calibrated to the ambient light inside thecontainer when the door is closed and which then triggers when light isdetected above ambient levels and door is closed.

2. A vibration sensor attached to wall of container which triggers onvibrations of an amplitude and/or frequency signature indicative offorced entry into the container. The duration of signal would also be afactor to consider. The algorithm could be derived from observations andtests or it could use a pattern recognition approach such as NeuralNetworks.

3. An infrared or carbon dioxide sensor could be used to detect humanpresence, although a carbon dioxide sensor would probably require aprolonged exposure.

4. Various motion sensors as discussed above can also be used, but wouldneed to be resistant to triggering on motion typical of cargo transport.Thus a trained pattern recognition algorithm might be necessary.

5. The Interior of the container can be flooded with waves (ultrasonicor electromagnetic) and the return signature evaluated by a patternrecognition system such as a neural network trained to recognize changesconsistent with the removal of cargo or the presence of a person orpeople. Alternately the mere fact that the pattern was changing could beindicative of human presence.

As discussed above and below, information from entry/person detectorcould be sent to communication network to notify interested parties ofcurrent status. Additionally, an audible alarm may be sounded and aphoto could also be taken to identify the intruder. Additionally, motionsensors such as an accelerometer on a wall or floor of a vehicle such asa container or an ultrasonic or optical based motion detector such asused to turn on residential lights and the like, can also be used todetect intrusion into a vehicle and thus are contemplated herein. Suchsensors can be mounted at any of the preferred locations disclosedherein or elsewhere in or on the vehicle. If a container, for example,is closed, a photocell connected to a pattern recognition system such asa neural network, for example can be trained to be sensitive to veryminute changes in light such as would occur when an intruder opens adoor or cuts a hole in a wall, ceiling or the floor of a vehicle even ona dark night. Even if there are holes in the vehicle that allow light toenter, the rate of change of this illumination can be detected and usedas an indication of an intrusion.

It is noteworthy that systems based on the disclosure above can beconfigured to monitor construction machinery to prevent theft or atleast to notify others that a theft is in progress.

The transmission of data obtained from imagers, or other transducers, toanother location, requiring the processing of the information, usingneural networks for example, to a remote location is an importantfeature of the inventions disclosed herein. This capability can permitan owner of a cargo container or truck trailer to obtain a picture ofthe interior of the vehicle at any time via telematics. When coupledwith occupant sensing, the driver of a vehicle can be recognized and theresult sent by telematics for authorization to minimize the theft orunauthorized operation of a vehicle. The recognition of the driver caneither be performed on the vehicle or an image of the driver can be sentto a remote location for recognition at that location.

Generally monitoring of containers, trailers, chassis etc. isaccomplished through telecommunications primarily with LEO orgeostationary satellites or through terrestrial-based communicationsystems such as a ubiquitous internet. These systems are commerciallyavailable and will not be discussed here. Expected future systemsinclude communication between the container and the infrastructure toindicate to the monitoring authorities that a container with aparticular identification number is passing a particular terrestrialpoint. If this is expected, then no action would be taken. The containeridentification number can be part of a national database that containsinformation as to the contents of the container. Thus, for example, if acontainer containing hazardous materials approaches a bridge or tunnelthat forbids such hazardous materials from passing over the bridge orthrough the tunnel, then an emergency situation can be signaled andpreventive action taken.

It is expected that monitoring of the transportation of cargo containerswill dramatically increase as the efforts to reduce terrorist activitiesalso increase. If every container that passes within the borders of theUnited States has an identification number and that number is in adatabase that provides the contents of that container, then the use ofshipping containers by terrorists or criminals should gradually beeliminated. If these containers are carefully monitored by satellite oranother communication system that indicates any unusual activity of acontainer, an immediate investigation can result and then the cargotransportation system will gradually approach perfection whereterrorists or criminals are denied this means of transporting materialinto and within the United States. If any container is found containingcontraband material, then the entire history of how that containerentered the United States can be checked to determine the source of thefailure. If the failure is found to have occurred at a loading portoutside of the United States, then sanctions can be imposed on the hostcountry that could have serious effects on that country's ability totrade worldwide. Just the threat of such an action would be asignificant deterrent. Thus, the use of containers to transporthazardous materials or weapons of mass destruction as well as people,narcotics, or other contraband and can be effectively eliminated throughthe use of the container monitoring system of at least one of theinventions disclosed herein.

Prior to the entry of a container ship into a harbor, a Coast Guard boatfrom the U.S. Customs Service can approach the container vessel and scanall of the containers thereon to be sure that all such containers areregistered and tracked including their contents. Where containerscontain dangerous material legally, the seals on those containers can becarefully investigated prior to the ship entering U.S. waters.Obviously, many other security precautions can now be conceived once theability to track all containers and their contents has been achievedaccording to the teachings of at least one of the inventions disclosedherein.

Containers that enter the United States through land ports of entry canalso be interrogated in a similar fashion. As long as the shipper isknown and reputable and the container contents are in the database,which would probably be accessible over the Internet, is properlyupdated, then all containers will be effectively monitored that enterthe United States with the penalty of an error resulting in thedisenfranchisement of the shipper, and perhaps sanctions against thecountry, which for most reputable shippers or shipping companies wouldbe a severe penalty sufficient to cause such shippers or shippingcompanies to take appropriate action to assure the integrity of theshipping containers. Intelligent selected random inspections guided bythe container history would still take place.

Although satellite communication is preferred, communication using cellphones and infrastructure devices placed at appropriate locations alongroadways are also possible. Eventually there will be a network linkingall vehicles on the highways in a peer-to-peer arrangement (perhapsusing Bluetooth, IEEE 802.11 (WI-FI), WiMAX, Wi-Mobile or other local,mesh or ad-hoc network) at which time information relative to containercontents etc. can be communicated to the Internet or elsewhere directlyor through this peer-to-peer network. It is expected that apseudo-noise-based or similar communication system such as a codedivision multiple access (CDMA) system, wherein the identifying code ofa vehicle is derived from the vehicle's GPS determined location, will bethe technology of choice for this peer-to-peer vehicle network or directinternet communication. It is expected that this network will be able tocommunicate such information to the Internet (with proper securityprecautions including encryption where necessary or desired) and thatall of the important information relative to the contents of movingcontainers throughout the United States will be available on theInternet on a need-to-know basis. Thus, law enforcement agencies canmaintain computer programs that will monitor the contents of containersusing information available from the Internet. Similarly, shippers andreceivers can monitor the status of their shipments through a connectiononto the Internet. Thus, the existence of the Internet or equivalent canbe important to the monitoring system described herein.

An alternate method of implementing the invention is to make use of acell phone or PDA. Cell phones that are now sold contain a GPS-basedlocation system as do many PDAs. Such a system along with minimaladditional apparatus can be used to practice the teachings disclosedherein. In this case, the cell phone, PDA or similar portable devicecould be mounted through a snap-in attachment system, for example,wherein the portable device is firmly attached to the vehicle. Thedevice can at that point, for example, obtain an ID number from thecontainer through a variety of methods such as a RFID, SAW or hardwiredbased system. It can also connect to a satellite antenna that wouldpermit the device to communicate to a LEO or GEO satellite system, suchas Skybitz as described above. Since the portable device would onlyoperate on a low duty cycle, the battery should last for many days orperhaps longer. Of course, if it is connected to the vehicle powersystem, its life could be indefinite. When power is waning, this factcan be sent to the satellite or cell phone system to alert theappropriate personnel. Since a cell phone contains a microphone, itcould be trained, using an appropriate pattern recognition system, torecognize the sound of an accident or the deployment of an airbag orsimilar event. It thus becomes a very low cost OnStar® type telematicssystem.

As an alternative to using a satellite network, the cell phone networkcan be used in essentially the same manner when a cell phone signal isavailable. All of the sensors disclosed herein can either beincorporated into the portable device or placed on the vehicle andconnected to the portable device when the device is attached to thevehicle. This system has a key advantage of avoiding obsolescence. Withtechnology rapidly changing, the portable device can be exchanged for alater model or upgraded as needed or desired, keeping the overall systemat the highest technical state. Existing telematics systems such asOnStar® can of course also be used with this system.

Importantly, an automatic emergency notification system can now be madeavailable to all owners of appropriately configured cell phones, PDAs,or other similar portable devices that can operate on a very low costbasis without the need for a monthly subscription since they can bedesigned to operate only on an exception basis. Owners would pay only asthey use the service. Stolen vehicle location, automatic notification inthe event of a crash even with the transmission of a picture forcamera-equipped devices is now possible. Automatic door unlocking canalso be done by the device since it could transmit a signal to thevehicle, in a similar fashion as a keyless entry system, from eitherinside or outside the vehicle. The phone can be equipped with abiometric identification system such as fingerprint, voice print, facialor iris recognition etc. thereby giving that capability to vehicles. Thedevice can thus become the general key to the vehicle or house, and caneven open the garage door etc. If the cell phone is lost, itswhereabouts can be instantly found since it has a GPS receiver and knowswhere it is. If it is stolen, it will become inoperable without thebiometric identification from the owner.

Using the any of the various communication systems described above, anautomatic crash notification system can be built. The crash can besensed by the airbag crash or rollover sensors or the deployment of theairbag event can be sensed to trigger the communication of the event.The system can be powered by the vehicle power or a battery can be usedthat has a very long life since the system would draw little currentuntil the event. An advantage of a self-powered system is that it can bemore easily retrofitted to existing vehicles. Additionally, aself-powered system would still operate on the loss of vehicle powerwhich can happen during a crash. It may be desirable to continue totransmit emergency notification signals even after the crash if helpdoes not arrive or to communicate with the crashed vehicle to obtainconfirming or additional information.

An energy harvesting unit based on vibrations or light can beincorporated to overcome battery loss due to leakage and maintain thebattery in a charged state for the life of the vehicle. Thisself-contained system can use a microphone, for example, to sense airbagdeployment and thus the only wiring required would be to thecommunication system which also could be contained within the unit. Insome cases, the unit can be on the vehicle safety bus where it couldderive both power and crash information. In this latter case, a backuppower supply in the form of a capacitor can be provided. Thecommunication system can be any of those mentioned above including asatellite based system such as provided by SkyBitz, Inc., the cellularphone system or, preferably, a ubiquitous internet system such as WiMAX.Such a ubiquitous system is not yet in service but the inventors believethat the arguments for such a system are overwhelming at least partiallydue to the inventions disclosed herein and thus it will occur probablyin time for the deployment of a universal automatic crash notificationsystem as described herein.

Any or all of the information obtained from occupancy and other onboardsensors can be part of the information sent to the remote location viathe communication or telematics system.

Other communication systems will also frequently be used to connect thecontainer with the chassis and/or the tractor and perhaps theidentification of the driver or operator. Thus, information can beavailable on the Internet showing what tractor, what trailer, whatcontainer and what driver is operating at a particular time, at aparticular GPS location, on a particular roadway, with what particularcontainer contents. Suitable security will be provided to ensure thatthis information is not freely available to the general public.Redundancy can be provided to prevent the destruction or any failure ofa particular site from failing the system.

This communication between the various elements of the shipping systemwhich are co-located (truck, trailer, container, container contents,driver etc.) can be connected through a wired or wireless bus such asthe CAN bus. Also, an electrical system such as disclosed in U.S. Pat.No. 5,809,437, U.S. Pat. No. 6,175,787 and U.S. Pat. No. 6,326,704 canalso be used in the invention.

In many cases, it is desirable to obtain and record additionalinformation about the cargo container and its contents. As mentionedabove, the weight of the container with its contents and thedistribution and changes in this weight distribution could be valuablefor a safety authority investigating an accident, for highwayauthorities monitoring gross vehicle weight, for container owners whocharge by the used capacity, and others. The environment that thecontainer and its contents have been subjected to could also besignificant information. Such things as whether the container wasflooded, exposed to a spill or leakage of a hazardous material, exposedto excessive heat or cold, shocks, vibration etc. can be importanthistorical factors for the container affecting its useful life,establishing liability for damages etc. For example, a continuousmonitoring of container interior temperature could be significant forperishable cargo and for establishing liability. Specifically,monitoring of the temperature can be used to determine whether theoperating parts of the container, e.g., the refrigeration unit, failsand thereby establish liability for damage to the perishable cargo withthe entity responsible for maintenance of the cargo container. In thiscase, data about the refrigeration unit could be transmitted to afacility operated by an entity responsible for maintenance of the cargocontainer, as discussed elsewhere herein, to enable them to act torectify failure of the refrigeration unit. Such an entity might leaserefrigerated cargo containers and once a failure of a refrigeration unitis detected, it could immediately notify the trucker or railroadoperator transporting the container to sideline the container until theperishable cargo therein can be transferred to another refrigeratedcargo container or the refrigeration unit fixed. Staff for fixingrefrigeration units could be strategically positioned around areas inwhich leased cargo containers travel, or are expected to travel.

With reference to FIG. 23A, in some cases, the individual cargo items498 can be tagged with RFID or SAW tags 499 (also representing a generalsensor system used to obtain data about the cargo item 498) and thepresence of this cargo in the container 480 could be valuableinformation to the owner of the cargo. One or more sensors on thecontainer that periodically read RFID tags could be required, such asone or more RFID interrogators 500 which periodically send a signalwhich will causes the RFID tags 499 to generate a responsive signal. Theresponsive signal generated by the RFID tags 499 will containinformation about the cargo item on which the RFID tag 499 is placed.This information may be any property or condition about the contents,such as temperature, presence of one or more chemicals, pressure, aradioactivity sensor, and other types of sensors discussed elsewhereherein.

Multiple interrogators or at least multiple antennas may be requireddepending on the size of the container. The RFID can be based on a SAWthus providing greater range for a passive system or it can also beprovided with an internal battery or ultracapacitor for even greaterrange. Energy harvesting can also be used if appropriate.

In one method for tracking packages in accordance with the invention,the interrogator 500 includes a processor and is programmed toperiodically interrogate the interior of the container 480 bytransmitting radio frequency waves into the interior of the container480. As known to known skilled in the art, the interrogator 500 receivesRF signals generated by the RFID tags 499, and the processor thereininterprets the received RF signals into an indication of the presence ofa specific cargo item 498 (with the signal possibly providinginformation about the cargo item 498). The processor in the interrogator500 can form a list of the contents of the container 480, i.e., theidentified cargo items 498, and provide this list to the communicationssystem 485 via a link thereto whereby the communication system 485transmits this list to one or more remote facilities.

An entity managing shipment of the cargo items 498, e.g., a packagedelivery service company, is thus able to known the location of everybox in every container 480, and the location of the container 480 whenit provides its location in the transmission to the remote facility. Thelocation of the container 480 may be provided by a positioning system486 on the container 480 (not shown in FIG. 3A).

Bi-directional communications are also possible whereby the managingentity can initiate the interrogator 500 to interrogate the interior ofthe container 480. Thus, interrogator 500 can either be initiated uponcommand from the remote facility, at a predetermined periodic intervaland/or upon detection of a condition which may give rise to a change inthe contents of the container 480, e.g., opening or closing of the dooras detected by a door status sensor 487 described elsewhere herein. Themanaging entity may perform an hourly update of the contents of itsmanaged containers 480 to ascertain when each cargo item 498 has beenremoved, and thus delivered, and can thereby track the efficiency of thedelivery personnel. Further, the bi-directional communications can beused to provide data about the cargo items 498 to the remote facility,e.g., when a new cargo item 498 is placed into the container, theinterrogator 500 could read the indicia convert it to an identificationand other information and then transmit this identification and otherinformation to the remote facility to begin tracking of this new cargoitem 498.

Similarly, for certain types of cargo, a barcode system mightacceptable, or another optically readable identification code. The cargoitems would have to be placed so that the identification codes arereadable, i.e., when a beam of light is directed over the identificationcodes, a pattern of light is generated which contains information aboutthe cargo item. In this regard, a system can be provided to notify thepersonnel placing the boxes 503 into the container 480 that the boxes503 are not placed properly, i.e., the indicia thereon cannot be read.Thus, one or more attempts may be made to read the indicia on a box whenit is first placed into the container and a warning provided, e.g., avisual and/or audible warning, if the box is placed such that theindicia is not readable by an optical scanner.

As shown in FIG. 23B, the cargo items in this case are boxes 503 havingvariable heights and all are arranged so that a space remains betweenthe top of the boxes 503 and the ceiling of the container 480. One ormore optical scanners 502, including a light transmitter and receiver,are arranged on the ceiling of the container and can be arranged to scanthe upper surfaces of the boxes 503, possibly by moving the length ofthe container 480 (via a movement mechanism such as an actuator coupledto the optical scanner which moves along one or more rails 468 whichextend along the length of the container 480), or through a plurality ofsuch sensors. During such a scan, patterns of light are reflected fromthe barcodes 501 on the upper surfaces of the boxes 503 and received bythe optical scanner 502. The patterns of light contain information aboutthe cargo items in the boxes 503. Receivers can be arranged at multiplelocations along the ceiling, in which case, an optical scanner includesan assembly of a light transmitter and one or more light receiversspaced apart from the light transmitter. Other arrangements to ensurethat a light beam traverses a barcode 501 and is received by a receivercan also be applied in accordance with the invention. As discussedabove, other tag technologies can be used if appropriate such as thosebased of magnetic wires.

By monitoring the data being determined using the sensors on the cargoitems 498, this data can be analyzed by a processor on the cargo items498 themselves, e.g., as part of the sensor system 499, or separate fromthe cargo items 498, e.g., on the container 480 (see processor 506 inFIG. 59A wherein the processor 506 is close to the RFID interrogator500), to determine the presence of a condition which has or is likely toaffect the status or health of the cargo items 498 has occurred or isforecast to occur. That is, the processor 506 determines whether thereis a problem with the cargo items 498 or a potential problem. As anexample, one problem is when a motion sensor is part of the sensorsystem 499 and motion of the cargo item 498 is analyzed relative tomotion of the container 480, and the processor 506 determines that thecargo item is moving considerably more than the container 480, whichsituation could be indicative of the cargo item 498 not being properlyrestrained and thus liable to fall over and cause damage to the cargoitem 498. Analysis of data obtained by the sensor systems 491 todetermine the existence or potential for a problem with the cargo item498 may involve use of pattern recognition technologies, such as atrained neural network.

The communication system 485 may be programmed to transmit a message toa remote facility only when the processor determines the presence of aproblem or potential problem with one or more cargo items 498. Thiswould conserve energy. Additionally, or alternatively, the sensorsystems 491 could be designed to trigger to obtain data about the cargoitem 498 when a door of the asset is closed after having been opened, achange in light in the interior of the container 480 is detected, basedon a predetermined or variable initiation time being regulated by aninitiation device, motion of the container 480 or change in motion ofthe container 480 is detected, vibration of the container 480 isdetected, and a predetermined internal or external event occurs whichwarrants obtaining data about the contents in view of the possibility ofa change in the status or health of the contents. In one embodiment, thesensor systems 491 on the cargo items 498 can be triggered to obtaineddata from the remote facility via the communication system 485, or frompersonnel on or about the vehicle on which the container 480 issituated.

When sensors are placed on each cargo item 498, the sensors are coupledto the communication system 485 and the location determining system 486using wires or wirelessly or a combination of both. If needed, apeer-to-peer and/or a mesh network can be integrated into the asset,i.e., the frame thereof, to enable all sensors on cargo items 498arranged in the interior of the asset to communicate with thecommunication system 485. This would most likely be applicable for largeships, trains and airplanes.

The ability to read barcodes and RFID tags provides the capability ofthe more closely tracking of packages for such organizations as UPS,Federal Express, the U.S. Postal Service and their customers. Now, insome cases, the company can ascertain that a given package is in fact ona particular truck or cargo transporter and also know the exact locationof the transporter.

In one method for tracking packages in accordance with the invention,the optical scanner 502 includes a processor and is programmed toperiodically generate a light beam and direct the light beam downward toread any barcodes 501 on boxes 503 in the field of view of the lightbeam. If movable, the optical scanner 502 is also periodically movedalong the rails 468 to ensure that most if not all of the area of theinterior of the container 480 is exposed to the light beam from theoptical scanner 502. As known to known skilled in the art, the opticalscanner 502 reads the barcodes 501, and the processor therein interpretsthe barcodes 501 into an indication of the presence of a particular box503 (with the barcode 501 possibly providing information about the box503). The processor in the optical scanner 502 can form a list of thecontents of the container 480, i.e., the identified boxes 503, andprovide this list to the communications system 485 via a link theretowhereby the communication system 485 transmits this list to one or moreremote facilities.

An entity managing shipment of the boxes 503, e.g., a package deliveryservice company, is thus able to known the location of every box inevery container 480, and the location of the container 480 when itprovides its location in the transmission to the remote facility. Thelocation of the container 480 may be provided by a positioning system486 on the container 480 (not shown in FIG. 3B).

Bi-directional communications are also possible whereby the managingentity can initiate the optical scanner 502 to read the barcodes 501from the boxes 503. Thus, optical scanner 502 can either be initiatedupon command from the remote facility, at a predetermined periodicinterval and/or upon detection of a condition which may give rise to achange in the contents of the container 480, e.g., opening or closing ofthe door as detected by a door status sensor 487 described elsewhereherein. The managing entity may perform an hourly update of the contentsof its managed containers 480 to ascertain when each box 503 has beenremoved, and thus delivered, and can thereby track the efficiency of thedelivery personnel. Further, the bi-directional communications can beused to provide data about the packages to the remote facility, e.g.,when a new box 503 is placed into the container, the optical scanner 502could read the indicia, convert it to an identification and otherinformation and then transmit this identification and other informationto the remote facility to begin tracking of this new box 503.

Frequently, a trailer or container has certain hardware such as racksfor automotive parts, for example, that are required to stay with thecontainer. During unloading of the cargo these racks, or othersub-containers, could be removed from the container and not returned. Ifthe container system knows to check for the existence of these racks,then this error can be eliminated. Frequently, the racks are of greatervalue then the cargo they transport. Using RFID tags and a simpleinterrogator mounted on the ceiling of the container perhaps near theentrance, enables monitoring of parts that are taken in or are removedfrom the container and associated with the location of container. Bythis method, pilferage of valuable or dangerous cargo can at least betracked.

Containers constructed in accordance with the invention will frequentlyhave a direct method of transmitting information to a satellite.Typically, the contents of the container are more valuable than thetruck or chassis for the case of when the container is not a trailer. Ifthe tractor, train, plane or ship that is transporting the container isexperiencing difficulties, then this information can be transmitted tothe satellite system and thus to the container, carrier, or cargo owneror agent for attention. Information indicating a problem with carrier(railroad, tractor, plane, boat) may be sensed and reported onto a bussuch as CAN bus which can be attached either wirelessly or by wires tothe container. Alternately, sensors on the container can determinethrough vibrations etc. that the carrier may be experiencing problems.The reporting of problems with the vehicle can come from dedicatedsensors or from a general diagnostic system such as described in U.S.Pat. No. 5,809,437 and U.S. Pat. No. 6,175,787, and herein. Whatever thesource of the diagnostic information, especially when valuable ordangerous cargo is involved, this information in coded form can betransmitted to a ground station, LEO or geostationary satellite asdiscussed above. Other information that can be recorded by containerincludes the identification of the boat, railroad car, or tractor andoperator or driver.

The experiences of the container can be recorded over time as acontainer history record to help in life cycle analysis to determinewhen a container needs refurbishing, for example. This history in codedform could reside on a memory that is resident on the container orpreferably the information can be stored on a computer file associatedwith that container in a database. The mere knowledge of where acontainer has been, for example, may aid law enforcement authorities todetermine which containers are most likely to contain illegalcontraband.

The pertinent information relative to a container can be stored on a tagthat is associated and physically connected to the container. This tagmay be of the type that can be interrogated remotely to retrieve itscontents. Such a tag, for example, could contain information as to whenand where the container was most recently opened and the contents of thecontainer. Thus, as containers enter a port, their tags can each beinterrogated to determine their expected contents and also to give awarning for those containers that should be inspected more thoroughly.In most cases, the tag information will not reside on the container butin fact will be on a computer file accessible by those who have anauthorization to interrogate the file. Thus, the container need onlyhave a unique identification number that cannot easily be destroyed,changed or otherwise tampered with. These can be visual and painted onthe outside of the container or an RFID, barcode or other objectidentification system can be used. Again, the tags can be based onpassive SAW technology to give greater range or could contain a batteryor ultracapacitor for even greater range. The tag can be in a sleep modeuntil receiving a wakeup call to further conserve battery power.

FIG. 24 shows a flow chart of the manner in which multiple assets may bemonitored using a data processing and storage facility 510, each assethaving a unique identification code. The location of each asset isdetermined at 511, along with one or more properties or characteristicsof the contents of each asset at 512, one or more properties of theenvironment of each asset at 513, and/or the opening and/or closing ofthe doors of each asset at 514. This information is transmitted to thedata processing and storage facility 510 as represented by 515 with theidentification code. Information about the implement being used totransport the asset and the individual(s) or company or companiesinvolved in the transport of the asset can also be transmitted to thefacility as represented by 516. This latter information could be enteredby an input device attached to the asset.

The data processing and storage facility 510 is connected to theInternet at 517 to enable shippers 518 to check the location andprogress of the asset, the contents of the asset, the environment of theasset, whether the doors are being opened and closed impermissibly andthe individual and companies handling the asset. The same information,or a subset of this information, can also be accessed by law enforcementpersonnel at 519 and maritime/port authorities at 520. Differententities can be authorized to access different items of information orsubsets of the total information available relating to each asset.

For anti-theft purposes, the shipper enters the manifest of the assetusing an input device 521 so that the manifest can be compared to thecontents of the asset (at 522). A determination is made at 523 as towhether there are any differences between the current contents of theasset and the manifest. For example, the manifest might indicate thepresence of contents whereas the information transmitted by the assetreveals that it does not contain any objects. When such a discrepancy isrevealed, the shipment can be intercepted at 524 to ascertain thewhereabouts of the cargo. The history of the travels of the asset wouldalso be present in the data facility 510 so that it can be readilyascertained where the cargo disappeared. If no discrepancy is revealed,the asset is allowed to proceed at 525.

Having the ability to transmit coded information to a satellite,ubiquitous internet, or other telematics system, using a low cost devicehaving a battery that lasts for many years opens up many other,previously impractical opportunities. Many of these opportunities arediscussed above and below and all are teachings of at least one of theinventions disclosed herein. In this section, opportunities related tomonitoring the environment in the vicinity of the container will bediscussed. Many types of sensors can be used for the purpose of exteriormonitoring including ultrasound, imagers such as cameras both with andwithout illumination including visual, infrared or ultraviolet imagers,radar, scanners including laser radar and phased array radar, othertypes of sensors which sense other parts of the electromagneticspectrum, capacitive sensors, electric or magnetic field sensors, andchemical sensors among others.

Cameras either with or without a source of illumination can be used torecord people approaching the container and perhaps stealing thecontents of the container. At the appropriate frequencies, (tetra Hertz,for example) the presence of concealed weapons can be ascertained asdescribed in Alien Vision: Exploring the Electromagnetic Spectrum WithImaging Technology (SPIE Monograph Vol. PM104) by Austin Richards.Infrared sensors can be used to detect the presence of animal lifeincluding humans in the vicinity of container. Radio frequency sensorscan sense the presence of authorized personnel having a keyless entrytype transmitter or a SAW, RFID or similar device of the proper design.In this way, the container can be locked as a safe, for example, andonly permit an authorized person carrying the proper identification toopen the container or other storage facility.

A pattern recognition system can be trained to identify facial or irispatterns, for example, of authorized personnel or ascertain the identityof authorized personnel to prevent theft of the container. Such apattern recognition system can operate on the images obtained by thecameras. That is, if the pattern recognition system is a neural network,it would be trained to identify or ascertain the identity of authorizedpersonnel based on images of such personnel during a training phase andthus operationally only allow such personnel to open the container,enter the container and/or handle the container.

A wide variety of smart cards, biometric identification systems (such asfingerprints, voice prints and Iris scans) can be used for the samepurpose. When an unauthorized person approaches the container, his orher picture can be taken and, in particular, if sensors determine thatsomeone is attempting to force entry into the container, that person'spicture can be relayed via the communication system to the properauthorities. Cameras with a proper pattern recognition system can alsobe used to identify if an approaching person is wearing a disguise suchas a ski mask or is otherwise acting in a suspicious manner. Thisdetermination can provide a critical timely warning and in some casespermit an alarm to be sounded or otherwise notify the properauthorities.

Capacitance sensors or magnetic sensors can be used to ascertain thatthe container is properly attached to a trailer. An RFID or barcodescanner on the container can be used to record the identification of thetractor, trailer, or other element of the transportation system. Theseare just a small sampling of the additional sensors that can be usedwith the container or even mounted on a tractor or chassis to monitorthe container. With the teachings of at least one of the inventionsdisclosed herein, the output of any of these sensors can now betransmitted to a remote facility using a variety of telematics methodsincluding communication via a low power link to the internet or asatellite, such as provided by the Skybitz Corporation as describedabove and others.

Thus, as mentioned above, many new opportunities now exist for applyinga wide variety of sensors to a cargo container or other object asdiscussed above and below. Through a communication system such as aubiquitous internet, a LEO or geostationary or other satellite system,critical information about the environment of container or changes inthat environment can be transmitted to the container owner, lawenforcement authorities, container contents owner etc. Furthermore, thesystem is generally low cost and does not require connection to anexternal source of power. The system generally uses low power from abattery that can last for years without maintenance,

Many of the sensor systems described above output data that can best beanalyzed using pattern recognition systems such as neural networks,cellular neural networks, fuzzy logic, sensor fusion, modular neuralnetworks, combination neural networks, support vector machines, neuralfuzzy systems or other classifiers that convert the pattern data into anoutput indicative of the class of the object or event being sensed. Oneinteresting method, for example, is the ZISC® chip system of SiliconRecognition Inc., Petaluna, Calif. A general requirement for the lowpower satellite monitoring system is that the amount of data routinelysent to the satellite be kept to a minimum. For most transmissions, thisinformation will involve the location of the container, for example,plus a few additional bytes of status information determined by themission of the particular container and its contents. Thus, the patternrecognition algorithms must convert typically a complex image or otherdata to a few bytes representative of the class of the monitored item orevent.

In some instances, the container must send considerably more data and ata more frequent interval than normal. This will generally happen onlyduring an exceptional situation or event and when the added batterydrain of this activity is justified. In this case, the system willsignal the satellite that an exception situation exists and to prepareto receive additional information.

Many of the sensors on the container and inside the container may alsorequire significant energy and thus should be used sparingly. Forexample, if the container is known to be empty and the doors closed,there is no need to monitor the interior of the container unless thedoors have been reopened. Similarly, if the container is stationary anddoors are closed, then continuously monitoring the interior of thecontainer to determine the presence of cargo is unnecessary. Thus, eachof the sensors can have a program duty cycle that depends on exterior orother events. In some applications either energy harvesting such assolar power or other source of power may be available eitherintermittently to charge the battery or continuously.

If the vehicle such as a container is stationary then usually themonitoring can take place infrequently and the battery is conserved.When the vehicle is in motion then energy is frequently available tocharge the battery and thus more frequent monitoring can take place asthe battery is charged. The technique in known as “energy harvesting”and involves, for example, the use of a piezoelectric material that iscompressed, bent or otherwise flexed thereby creating an electriccurrent that can be used with appropriate circuitry to charge thebattery. Other methods include the use of a magnet and coil where themagnet moves relative to the coil under forces caused by the motion ofthe vehicle.

Since the duty cycle of the sensor system may vary considerably, andsince any of the sensors can fail, be sabotaged or otherwise be renderedincapable of performing its intended function either from time,exposure, or intentionally, it is expected that some or all of thesensors will be equipped with a diagnostic capability. The communicationsystem will generally interrogate each sensor or merely expect atransmission from each sensor and if that interrogation or transmissionfails or a diagnostic error occurs, this fact will be communicated tothe appropriate facility. If, for example, someone attempts to cover thelens of a camera so that a theft would not be detected, the mere factthat the lens was covered could be reported, alerting authorities thatsomething unusual was occurring.

As mentioned previously, there are times when the value of the contentsof a container can exceed the value of the tractor, chassis andcontainer itself. Additionally, there are times when the contents of thecontainer can be easily damaged if subjected to unreasonable vibrations,angles, accelerations and shocks. For these situations, an inertialmeasurement unit (IMU) can be used in conjunction with the container tomonitor the accelerations experienced by the container (or the cargo)and to issue a warning if those accelerations are deemed excessiveeither in magnitude, duration, or frequency or where the integrations ofthese accelerations indicate an excessive velocity, angular velocity orangular displacement. Note that for some applications in order tominimize the power expended at the sensor installation, the IMUcorrection calculations based on the GPS can be done at an off sensorlocation such as the receiving station of the satellite information.

If the vehicle operates on a road that has previously been accuratelymapped, to an accuracy of perhaps a few centimeters, then the analysissystem can know the input from the road to the vehicle tires and thus tothe chassis of the trailer. The IMU can also calculate the velocity ofthe trailer. By monitoring the motion of the container when subjected toa known stimulus, the road, the inertial properties of the container andchassis system can be estimated. If these inertial properties are knownthan a safe operating speed limit can be determined such that theprobability of rollover, for example, is kept within reasonable bounds.If the driver exceeds that velocity, then a warning can be issued.Similarly, in some cases, the traction of the trailer wheels on theroadway can be estimated based on the tendency of a trailer to skidsideways. This also can be the basis of issuing a warning to the driverand to notify the contents owner especially if the vehicle is beingoperated in an unsafe manner for the road or weather conditions. Sincethe information system can also know the weather conditions in the areawhere the vehicle is operating, this added information can aid in thesafe driving and safe speed limit determination. In some cases, thevibrations caused by a failing tire can also be determined. For thosecases where radio frequency tire monitors are present, the container canalso monitor the tire pressure and determine when a dangerous situationexists. Finally, the vehicle system can input to the overall system viatelematics when the road is covered with ice or when it encounters apothole.

Thus, there are many safety related aspects to having sensors mounted ona container and where those sensors can communicate periodically with aLEO or other satellite, the internet, or other communication system, andthereafter to the Internet or directly to the appropriate facility. Someof these rely on an accurate IMU. Although low cost IMUs are generallynot very accurate, when they are combined using a Kalman filter with theGPS system, which is on the container as part of the tracking system,the accuracy of the IMU can be greatly improved, approaching that ofmilitary grade systems.

The discussion above has concentrated, in part, on containers thatcontain cargo where presumably this cargo is shipped from one company ororganization to another. This cargo could be automotive parts, animals,furniture, weapons, bulk commodities, machinery, fruits, vegetables, TVsets, or any other commonly shipped product. What has been describedabove is a monitoring system for tracking this cargo and makingmeasurements to inform the interested parties (owners, law enforcementpersonnel etc.) of the status of the container, its contents, and theenvironment. This becomes practical when a ubiquitous internet or asatellite system exists such as the Skybitz, for example, LEO orgeostationary satellite system coupled with a low cost low power smallGPS receiver and communication device capable of sending informationperiodically to the internet or satellite. Once the satellite hasreceived the position information from the container, for example, thisinformation can be relayed to a computer system wherein the exactlocation of the container can be ascertained. Additionally, if thecontainer has an RFID reader, the location of all packages having anRFID tag that are located within the container can also be ascertained.

The accuracy of this determination is currently now approximately 20meters. However, the ionosphere caused errors in GPS signals received bycontainer receiver can be determined from a variety of differential GPSsystems and that information can be coupled with the information fromthe container to determine a precise location of the container toperhaps as accurate as a few centimeters. This calculation can be doneat any facility that has access to the relevant DGPS corrections and thecontainer location. It need not be done onboard the container. Usingaccurate digital maps the location of the container on the earth can beextremely precisely determined. This principle can now be used for otherlocation determining purposes. The data processing facility thatreceives the information from the asset via satellites can also know theDGPS corrections at the asset location and thus can relay to the vehicleits precise location.

Many transmission modes exist including cellular phone systems,satellite communications and the Internet. The Internet systems can bebroken into two types, those in use now that are available only atparticular “hot-spots” and a ubiquitous internet which by definition isavailable almost everywhere. The use of ubiquitous internet is believedto be unique to the inventions herein as the inventors may have been thefirst to recognize that ubiquitous internet would become available artleast partially due to the inventions herein and can be counted on toprovide the sole system for communication from various vehiclesincluding automobiles, trucks and truck trailers, storage tanks andshipping containers replacing all other communication systems. Theirvision is now being realized through such systems as WiMAX.

Although the discussion above has centered, in part, on cargotransportation as an illustrative example, at least one of theinventions disclosed herein is not limited thereto and in fact can beused with any asset whether movable or fixed where monitoring for any ofa variety of reasons is desired. These reasons include environmentalmonitoring, for example, where asset damage can occur if thetemperature, humidity, or other atmospheric phenomena exceeds a certainlevel. Such a device then could transmit to the telecommunicationssystem when this exception situation occurred. It still could transmitto the system periodically, perhaps once a day, just to indicate thatall is OK and that an exceptional situation did not occur.

Referring to FIG. 39, another example could be the monitoring of avacation home 210 during the months when the home 210 is not occupied.Of course, any home could be so monitored even when the occupants leavethe home unattended for a party, for example. The monitoring systemwould include one or more sensors 214 and a processor 212 coupledthereto, e.g., via wires or wirelessly, and including or associated witha communications unit, and could determine whether the house is on fire,being burglarized, or whether temperature is dropping to the point thatpipes could freeze due to a furnace or power failure. Such a systemcould be less expensive to install and maintain by a homeowner, forexample, than systems supplied by ADT, for example. Monitoring of a realestate location could also be applied to industrial, governmental andany other similar sites. Any of the sensors 214 may be electromagnetic,cameras, ultrasound, capacitive, chemical, moisture, radiation,biological, temperature, pressure, radiation, etc. could be attached tosuch a system which would not require any other electrical connectioneither to a power source 216 or to a communication source such as atelephone line which is currently require by ADT, for example. In fact,most currently installed security and fire systems require both a phoneand a power connection. If a power source is available, it can be usedto recharge the batteries or as primary power. Each sensor 214 may beassociated or integral with its own power source 216 so that each sensorsystem 214 operates without wires or power from an external source.

In one particular embodiment, the sensors 214 include an intruder sensorwhich may be associated with the windows and/or doors of the house 210,a fire detector, a smoke detector, a water detector (to detect floodingfrom broken pipes or leaks in the roof), pollution sensors, and othersensors which detect conditions which may lead to or actually causedamage to the house 210. Such sensors 214 could also monitor theexterior environment or area around the house 210. The monitoring systemcould be programmed to periodically obtain information from the sensorsand transmit the information to the remote monitoring facility 218, orthe processor 212 and communications unit associated therewith may bedesigned for bi-directional communications so that the remote monitoringfacility could initiate the monitoring system to obtain information fromthe sensors about the house 210.

The processor 212 would also include its location, i.e., the location ofthe house 210, in the transmission to the remote facility 218 which maybe pre-programmed into the processor 212.

The remote monitoring facility 218 would receive the transmission, e.g.,using any of the techniques described above such as using the ubiquitousInternet, and then could dispatch appropriate personnel based on thecontent of the communication. For example, if a water detector was onesensor 214 and it detects the presence of water, it could send aplumbing contractor. If a smoke detector was one sensor 214, the remotefacility could instruct a fire department to respond and provide detailsof the house 210.

To prevent a lack of power from preventing the sensors 214 or processorand communications unit 216 from transmitting information to the remotefacility 218, the power source 216 for the processor 212 and/or sensorsystems 214 may be designed to use energy harvesting, e.g., energyobtained from available sources such as the solar energy or createdduring routine, normal actions. The power source 216 could be designedas a battery which is charged, e.g., when a connection to a power gridis available. In this manner, even if the power to the house 210 is shutoff by the homeowner or by thieves, the sensors 214 and processor 212will still have available power.

The foregoing enables wireless and powerless monitoring of the house210. To conserve power and increase the service life of the arrangement,the occurrence of an internal or external event, or the absence of anevent for a time period, requiring a change in the frequency ofmonitoring of the fixed structure may be detected by appropriatesensors, e.g., a break-in sensor. In this case, the rate at which thesensors 214 obtain information about the house 210 in response to thedetected occurrence of an internal or external event may be changed.Also, when a condition causing damage to or which might lead to damageto the house 210 is determined to be present at the house 210 by theremote facility 218 based on the transmitted information, at least onereactive system 220 in the house 210 may be controlled by the remotefacility 218 based on the transmitted information about the fixedstructure obtained by the sensors 214. The reactive system 220 may be analarm, a fire extinguisher system and the like.

The same system for monitoring the house 210 can be used to monitorother fixed structures such as boats, parked airplanes. Although for aboat or airplane which can be moved, the location of the boat orairplane may be provided by a position or location determining system onthe boat or airplane and then provided to the processor 212.

Of particular importance, this system and techniques can be applied togeneral aviation and the marine community for the monitoring of flightand boat routings. For general aviation, this or a similar system can beused for monitoring the unauthorized approach of planes or boats topublic utilities, government buildings, bridges or any other structureand thereby warn of possible terrorist activities.

Portable versions of this system can also be used to monitor livingobjects such as pets, children, animals, and other objects such as cars,and trucks, or any other asset. What is disclosed herein therefore is atruly general asset monitoring system where the type of monitoring isonly limited by requirement that the sensors operate under low power andthe device does not require connections to a power source, other thanthe internal battery, or a wired source of communication. Thecommunication link is generally expected to be via a transmitter and aLEO, geostationary or other satellite, however, it need not be the caseand communication can be by cell phone, an ad hoc peer-to-peer network,IEEE 801.11, Bluetooth, or any other wireless system or directly to theinternet. Thus, using the teachings of at least one of the inventionsdisclosed herein, any asset can be monitored by any of a large varietyof sensors and the information communicated wireless to another locationwhich can be a central station, a peer-to-peer network, a link to theowner's location, or, preferably, to the Internet

Additional areas where the principles of the invention can be used formonitoring other objects include the monitoring of electric fieldsaround wires to know when the wires have failed or been cut, themonitoring of vibrations in train rails to know that a train is comingand to enable tracking of the path of trains, the monitoring ofvibrations in a road to know that a vehicle is passing, the monitoringof temperature and/or humidity of a road to signal freezing conditionsso that a warning could be posted to passing motorists about theconditions of the road, the monitoring of vibrations or flow in a oilpipe, or other conduit through which a fluid flows, to know if the flowof oil has stopped or part of it is being diverted so that adetermination may be made if the oil is being stolen, the monitoring ofinfrared or low power (MIR) radar signal monitoring for perimetersecurity, the monitoring of animals and/or traffic to warn animals thata vehicle is approaching to eliminate car to animal accidents and themonitoring of fluid levels in tanks or reservoirs. It is also possibleto monitor grain levels in storage bins, pressure in tanks, chemicals inwater or air that could signal a terrorist attack, a pollution spill orthe like, carbon monoxide in a garage or tunnel, temperature orvibration of remote equipment as a diagnostic of pending system failure,smoke and fire detectors and radiation. In each case, one or moresensors is provided that have been designed to perform the appropriate,desired sensing, measuring or detecting function and a communicationsunit is coupled to the sensor(s) to enable transmission of theinformation obtained by the sensor(s). A processor can be provided tocontrol the sensing function, i.e., to enable only periodic sensing orsensing conditioned on external or internal events. For each of theseand many other applications, a signal can be sent to a satellite,internet or other telematics system to send important information to aneed-to-know person, monitoring computer program, the Internet etc.

Three other applications of at least one of the inventions disclosedherein need particular mention. Periodically, a boat or barge impactswith the structure of a bridge resulting in the collapse of a road,railroad or highway and usually multiple fatalities. Usually such anevent can be sensed prior to the collapse of the structure by monitoringthe accelerations, vibrations, displacement, or stresses in thestructural members. When such an event is sensed, a message can be sentto a satellite and/or forwarded to the Internet, and thus to theauthorities and to a warning sign or signal that has been placed at alocation preceding entry onto the bridge. Alternately, the sensingdevice can send a signal directly to the relevant sign either inaddition or instead of to a satellite or the internet.

Sometimes the movement of a potentially hazardous cargo in itself is notsignificantly unless multiple such movements follow a pattern. Forexample, the shipment of moderate amounts of explosives toward a singlelocation could signify an attack by terrorists. By comparing the motionof containers of hazardous materials and searching for patterns, perhapsusing neural networks, fuzzy logic and the like, such concentrations ofhazardous material can be forecasted prior to the occurrence of adisastrous event. This information can be gleaned from the total pictureof movements of containers throughout a local, state or national area.Similarly, the movement of fuel oil and fertilizer by itself is usuallynot noteworthy but in combination using different vehicles can signal apotential terrorist attack.

Many automobile owners subscribe to a telematics service such asOnStar®. The majority of these owners when queried say that theysubscribe so that if they have an accident and the airbag deploys, theEMS personnel will be promptly alerted. This is the most commonlydesired feature by such owners. A second highly desired feature relatesto car theft. If a vehicle is stolen, the telematics services can trackthat vehicle and inform the authorities as to its whereabouts. A thirdhighly desired feature is a method for calling for assistance in anyemergency such as the vehicle becomes stalled, is hijacked, runs off theroad into a snow bank or other similar event. The biggest negativefeature of the telematics services such as OnStar® is the high monthlycost of the service.

At least one of the inventions described herein can provide the threeabove-mentioned highly desired services without requiring a high monthlyfee. A simple device that communicates to a satellite, the internet orother telematics system can be provided, as described above, thatoperates either on its own battery and/or by connecting to the cigarettelighter or similar power source. The device can be provided with amicrophone and neural network algorithm that has been trained torecognize the noise signature of an airbag deployment or the informationthat a crash transpired can be obtained from an accelerometer or IMU.Thus, if the vehicle is in an accident, the EMS authorities can beimmediately notified of the crash along with the precise location of thevehicle. Similarly, if the vehicle is stolen, its exact whereabouts canbe determined through an Internet connection, for example. Finally, adiscrete button placed in the vehicle can send a panic signal to theauthorities via a telematics system. Thus, instead of a high monthlycharge, the vehicle owner would only be charged for each individualtransmission, which can be as low as $0.20 or a small surcharge can beadded to the price of the device to cover such costs through averagingover many users. Such a system can be readily retrofitted to existingvehicles providing most of advantages of the OnStar® system, forexample, at a very small fraction of its cost. The system can reside ina “sleep” mode for many years until some event wakes it up. In the sleepmode, only a few microamperes of current are drawn and the battery canlast the life of the vehicle. A wake-up can be achieved when the airbagfires and the microphone emits a current. Similarly, a piezo-generatorcan be used to wake up the system based on the movement of a mass ordiaphragm displacing a piezoelectric device which then outputs someelectrical energy that can be sensed by the system electronics.Similarly, the system can be caused to wake up by a clock or thereception of a proper code from an antenna. Such a generator can also beused to charge the system battery extending its useful life. Such anOnStar®-like system can be manufactured for approximately $100,depending on production volume and features.

The invention described above can be used in any of its forms to monitorfluids. For example, sensors can be provided to monitor fuel or oilreservoirs, tanks or pipelines and spills. Sensors can be arranged in,on, within, in connection with or proximate a reservoir, tank orpipeline and powered in the manner discussed above, and coupled to acommunication system as discussed above. When a property ofcharacteristic of the environment is detected by the sensor, forexample, detection of a fluid where none is supposed to be (which couldbe indicative of a spill), the sensor can trigger a communication systemto transmit information about the detection of the fluid to a remotesite which could send response personnel, i.e., clean-up personnel. Thesensors can be designed to detect any variables which could providemeaningful information, such as a flow sensor which could detectvariations in flow, or a chemical sensor which could detect the presenceof a harmful chemical, biological agent or a radiation sensor whichcould detect the presence of radioactivity. Appropriate action could betaken in response to the detection of chemicals or radioactivity.

Telematics for Storage Tanks

What follows is a discussion of remote monitoring the level of a fluidin a storage tank or container as well as other properties of a tank,its environment and its contents. The determination of the level of afluid in a tank has been the subject of many patents, books and otherpublished articles and papers (see, for example, Measurement and Controlof Liquid Level (An Independent learning module from the InstrumentSociety of America) by Chun H. Cho, which describes several suchmethods). A combination of any of these methods with a low powerconsumption, long life telematics system permitting the remotemonitoring of a fixed or movable storage tank and its contents andenvironment over long periods of time without intervention is notbelieved to be available. With the availability of the system describedherein, storage tanks or other fluid storage structures or housingsplaced anywhere in the world can be monitored from any other place inthe world for fluid level, tampering, theft of contents or the entiretank, fire, excessive temperature, usage, etc. without maintenance forseveral years.

FIG. 25 is a side view of a Frac tank, such as supplied by e-Tank Inc,of Massillon, Ohio, containing a level monitoring system and othersensors in accordance with the invention. FIG. 26 is a perspective viewof an oil or chemical storage tank containing a level monitoring systemin accordance with the invention.

One preferred implementation of such a system for use with the Frac tanka schematically shown in FIG. 25 and the storage tank as schematicallyshown in FIG. 26 is described with reference to FIGS. 27 and 28. In amost basic embodiment, an interior sensor system is arranged on ahousing of the storage tank or other fluid-storage structure and isarranged to obtain information about any fluid in the interior of thehousing, this information can be the presence of fluid in the tankand/or the level of fluid in the tank or other properties of the fluid.A location determining system is also arranged on the housing andmonitors the location of the tank, i.e., either is provided with aninitial position and monitors change in that position, for movabletanks, or is provided with a device to enable it to determine itsposition. A communication system is coupled to the interior sensorsystem and the location determining system, and possibly even arrangedon the housing itself, and transmits the information about the fluid inthe interior of the housing and the location, or identification, of thetank to a remote facility. The remote facility may be any facility whichmonitors the contents of the tank, including possibly multiplefacilities, all of which are concerned with the contents and conditionof the tank or the fluid therein. Instead of being mounted on thehousing itself, the communication system may be arranged in closeproximity to the housing and coupled to the interior sensor system andlocation determining system via wires or in a wireless manner.

The level measurement in this example is accomplished using one or morewave-receiving devices 606, such as an ultrasonic transducermanufactured by Murata and described in the '572 patent mentioned above,and a reference target 601, which may donut-shaped. Each wave-receivingdevice 606 directs waves at an upper surface of the fluid when presentin the interior of the tank, when it is a wave transmitter, oralternatively receives waves, e.g., electromagnetic waves, from thefluid when it is, for example, an optical imager. Preferably, each wavereceiving device 606 is sealed into an enclosure which prevents it frombeing damaged by the fluid, i.e., liquid or gas in the interior of thehousing of the tank,

Each wave-receiving device 606 can be mounted to or in the top wall 602on the inside of any of the above mentioned tanks such that itsoperative field of view extends downward toward the fluid in the tank,whether downward toward the bottom of the tank or at an angle to a sideof the tank. A control unit/processor is provided to control the mannerin which each wave-transmitting device 606 emits ultrasonic orelectromagnetic waves, and the control unit/processor is shownschematically as 604, which unit also includes a location determiningsystem as described above. The location determining system and controlunit/processor may be arranged apart from one another, and possiblyalongside the housing of the tank or on another face of the tank, e.g.,a side of the tank. When the tank is fixed, its location can bedetermined on initial installation of the system and the tank isassigned an identification number which is then transmitted with thefluid information.

When the wave-receiving device 606 is an ultrasonic transceiver, e.g.,an ultrasonic wave transmitter/receiver, each time the wave-transducer606 emits an ultrasonic pulse, a reflection is obtained from the fluidsurface and also from the reference target 601. The receive reflectionsare analyzed by the control unit processor 604. In one embodiment, thecontrol unit/processor 604 is provided with information about thedistance between the wave-receiving device 606 and the reference target601 in its field of view. In this case, since the location of thereference target 601 relative to the wave-receiving device 606 is knownthe speed of sound in the tank can be calculated, the effects oftemperature and gas chemical makeup can be determined. A ratio of theecho times from the target 601 and fluid enables the controlunit/processor 604 coupled to the wave-receiving device 606 to determinethe location of the fluid surface. Knowing also the dimensions of thetank, the control unit/processor 604 can also determine the quantity offluid in the tank. A key advantage therefore of this system is that itis independent of gas composition and temperature. Additional referencetargets can of course be added if it is desired to take into account theeffects in gradation in the speed of sound caused by either thetemperature or gas composition.

This system of course only measures the fluid level at one location, thelocation impacted by the transmitted ultrasonic waves, and thus somemethod of determining the rotations about the horizontal axes of thetank may also be incorporated, at least for tanks that are movable suchas the Frac tank shown in FIG. 25. One method is to use multiple systemsof the type described herein (noting multiple wave-receiving devices 606in FIG. 26) or the incorporation of one or more tilt sensors 603 shownin FIG. 25, such as those manufactured by Fredriks of Huntingdon, Pa.and described in the '572 patent. If the geometry of the tank is knownand the level of the fluid is measured at one appropriate point, thenwith the added information from a tilt or angle sensor 603, the quantityof the fluid in the tank can be accurately determined. Indeed, it hasbeen established that by using trained pattern recognition techniques,knowing only three parameters about a fluid tank, it is possible tooperatively and accurately determine the quantity of fluid in the tank,even when the tank is subject to inclination. This is discussed in U.S.Pat. No. 6,892,572, incorporated by reference herein. Other moreaccurate angle gages are available as can be determined by one withordinary skill in the art and the Fredriks sensors discussed herein arefor illustration purposed only.

Frac tanks are often vented when a working site. FIG. 27 shows onepreferred method of determining the level of a fluid in a tank that isindependent on temperature or the speed of sound. FIG. 28 is a schematicillustration of the method of FIG. 27.

In some embodiments, the control unit/processor 604 is arranged tocompensate for thermal and/or gas density gradients in the interior ofthe tank. Different ways in which the received waves can be analyzed andprocessed while compensating for thermal and/or gas density gradientsare known to those skilled in the art. Compensation for gas densitygradients is particularly appropriate when using ultrasonic sensors andthus the processor which receives information about the ultrasonic wavesreflected from the upper surface of the liquid and determines thedistance between the ultrasonic sensor and the upper surface of theliquid (which enables a determination of the level of fluid in thestorage tank) would also be programmed to compensate for such gasdensity gradients (possibly in a manner described below). Any additionalgas density sensors which would be required to determine gaseousstratification of the area above the liquid may be mounted to thehousing.

In an embodiment described above, each wave receiving device 606receives waves from the upper surface of the fluid and from itsassociated reference target 601 so that the control unit/processor 604can analyze the waves and determine the level of fluid in the tank,since it knows the distance between each wave receiving device 606 andits associated reference target 601. In another embodiment, the controlunit/processor 604 compares waves received by each wave receiving device606 at different times and obtains information about the fluid in thetank based on the comparison of the waves received by the wave receivingdevice 606 at different times. When multiple wave receiving devices areprovided, the control unit/processor analyzes waves received by the wavereceiving devices 606 and obtains information about the fluid in thetank on the analysis of these waves.

Other sensors can be incorporated into the storage tank monitoringsystem as described with regard to shipping containers or truck trailersdescribed elsewhere herein. For example, low power chemical orbiological sensors can be incorporated to monitor the chemical nature ofthe contents of the tank. Similarly, temperature, pressure or othersensors can be added such as a camera that monitors the environmentsurrounding the tank and alerts the tank owner when the tank isapproached or breached. Additional sensors include MIR leakagedetectors, sound, light, inertial sensors, radar, etc. Magnetic or othersensors, for example, can detect the approach of a truck that might beused to move the tank. As such, in other embodiments of the invention,the interior sensor system includes one or more additional sensors 605for performing any one of a number of different functions, and which arecoupled to the control unit/processor 604. For example, a chemicalsensor may be provided to monitor the chemical nature of the fluid orvapor in the tank, and an exterior or environmental sensor may beprovided to monitor an environment around the tank to obtain informationabout the environment around the tank. Additional sensors include atemperature sensor, a pressure sensor, a carbon dioxide sensor, ahumidity sensor, a hydrocarbon sensor, a narcotics sensor, a mercuryvapor sensor, a radioactivity sensor, a microphone, an electromagneticwave sensor, electric or magnetic field sensor and a light sensor.

As mentioned, other fluid level determining systems can also be used andall such systems are within the scope of this invention. Once a levelsystem has been chosen, then it can be combined with a satellitecommunication system, such as provided by SkyBitz, Inc., orinternet-based monitoring system in the same or similar manner as theshipping container monitoring systems discussed elsewhere herein. Thus,once the interior sensor system in any of the embodiments describedabove obtains information about the fluid in the tank and optionaladditional information about the tank, it provides this information to acommunication system which may also be housed in the same housing ascontrol unit/processor 604. The communication system directs thisinformation along with information about the location of the tankobtained from the location determining system to one or more remotefacilities 607, using for example, a satellite link, an internet linkand the like.

To optimize monitoring of the tank, the control unit/processor mayinclude an initiation device for periodically initiating the wavereceiving device(s) 606, and/or other sensors when present, to obtaininformation about the fluid in the tank and/or the condition of thetank. A wakeup sensor system may thus be provided for detecting theoccurrence of an internal or external event, or the absence of an eventfor a time period, requiring a change in the frequency of monitoring ofthe tank. The initiation device is coupled to the wakeup sensor systemand arranged to change the rate at which it initiates the wave receivingdevice(s), or wave transmitting device(s), 606 and/or other sensors toobtain information about the fluid in the tank and/or the condition ofthe tank in response to the detected occurrence of an internal orexternal event by the wakeup sensor system. The initiation device andwakeup sensor system may be integrated into the control unit/processor604 or separate therefrom.

In one embodiment, a motion or vibration detection system is arranged todetect motion or vibration of the tank or a part thereof. The interiorsensor system, e.g., the wave receiving device(s) 606, are coupled tothe motion or vibration detection system and obtain information aboutthe fluid of the interior of the housing only after the tank or a partthereof is determined to have moved from a stationary position orvibrated. Similarly, a wakeup sensor system can be mounted on thehousing of the tank for detecting the occurrence of an internal orexternal event relating to the condition or location of the fluid in thehousing or the tank. The communication system may be coupled to thewakeup sensor system and arranged to transmit a signal relating to thedetected occurrence of an internal or external event. Whenever desiredor necessary, a memory unit may be coupled to the control unit/processor604 or part thereof and stores data relating to the location of the tankand the fluid in the interior of the housing. The motion or vibrationdetection system and wakeup sensor system may be integrated into thecontrol unit/processor 604 or separate therefrom.

A motion sensor may be arranged on the housing for monitoring motion ofthe housing, when the housing is in particular a movable fluid storagetank such as a Frac tank, and an alarm or warning system coupled to themotion sensor and which is activated when the motion sensor detectsdangerous motion of the housing. The motion sensor and alarm or warningsensor system may be integrated into the control unit/processor 604 orseparate therefrom. The motion sensor may be a flux gate compass whichis designed to determine if the tank has been moved.

The interior sensor system, e.g., the wave receiving device(s) 606, thelocation determining system and the communication system preferably allhave low power requirements. A battery, e.g., a rechargeable battery,may be coupled to the interior sensor system, the location determiningsystem and the communication system for providing power thereto. Thebattery may be supplemented with an energy harvesting system.

In addition to information being obtained based on changes in thecondition or state of the housing, it is also possible to cause theinterior sensor system to obtain information upon receipt of a commandfrom the remote facility 607. In this case, the link between thecommunications device in the control unit/processor 604 isbi-directional and allows for reception of a command from a remotefacility 607 to cause the wave receiving device(s) 606 to operate andobtain information about the fluid in the tank. This information issubsequently transmitted to the remote facility 607. In another case,the interior sensor system includes a combination of optical andultrasonic or other wave-type receiving or transceiving devices, eachsuch device being represented by reference numeral 606. An opticalsystem 606 is mounted on the housing to characterize the contents in thetank, e.g., determine the nature of the fluid, its identity orcomposition, and an ultrasonic system 606 is used to determine the fluidlevel. Both such systems would be coupled to the control unit/processor604 which would coordinate information gathering by both systems andtransmit messages to the remote facility 607 about the nature of thefluid and its level, along with a location or position indicationobtained from the location determining system. Such an optical systemmay be as described herein and would generally include an optical sensorwhich obtains images of the fluid and can analyze the images todetermine the nature of the fluid. This may be achieved using patternrecognition technologies.

In another embodiment, only optical systems are used, represented byreference numeral 606 in FIGS. 25 and 26, since an optical system couldalso determine the level of fluid in a tank. In this case, one or moremarkings can be provided along the inner surface of the tank, or onother members extending along the height of the tank in the interior ofthe tank. The optical system obtains images including the marking(s) andcan analyze the images to determine the level of the fluid. In oneparticular embodiment, the optical system is designed to project scaleson the inner surface of three walls of the housing, or at threedifferent locations on the inner surface of the housing wall or walls,and obtain images of the wall(s) at the projected locations of thescales. This information is used to derive the level of fluid in thetank, by a processor which may use a trained pattern recognitiontechnique such as a trained neural network. The training may involveobtaining images when different, but known, levels of fluid are presentin the tank, and the tank is at different inclinations. In this case,images are obtained for different tank levels and different inclinationsand inputted into a neural network generating program which provides aneural network which is capable of outputting a fluid level uponreceiving images of the three projected scales.

In one embodiment, it is envisioned that modulated light may be used fortank level measurements.

In a preferred embodiment, a single ultrasonic wave receiving device 606is mounted to an inner surface of the housing and is sealed into anenclosure to prevent damage caused by any fluids in the housing. A twoaxis tilt or angle sensor 605 is also mounted to the housing and thissensor 605 as well as the wave receiving device 606 are coupled to thecontrol unit/processor 604. The control unit/processor 604 receivessignal corresponding to or representative of the waves received by thewave receiving device 606, or information derived therefrom at the wavereceiving device 606, along with the information about inclination ofthe housing from the tilt sensor 605 and the location of the tank fromthe location determining system and forms a message for transmission tothe remote facility 607.

The remote facility 607 which monitors the storage tanks can receivemessages, e.g., via the Internet or a satellite link, each containingthe location of the tank and information about the fluid therein. Theremote facility 607 can also be designed to enable monitoring ofselected ones or all of the storage tanks via the wave receiving devicesif a bi-directional communications device is coupled to or part of thecontrol unit/processor 604 associated with each storage tank. A reportabout the storage tanks can be compiled by a processor or control unitat the remote facility 607 and alarms or warnings provided to monitoringpersonnel if a problem is detected with any of the fluids in the storagetanks or a problem is detected with any of the storage tanks.

When the communication system in the control unit/processor 604 on thehousing of the tank allows for bi-directional communications, the tankcan be provided with one or more controlled systems or components whichcan be commanded by the remote facility 607 to undertake a specificaction. This would be in addition to the ability of the remote facility607 to command the interior sensor system, e.g., the wave receivingdevice(s) 606 to undertake a reading. Such controlled systems may be afire extinguisher on the tank or a cleaning system, a valuing system andthe like. Any of these such systems can be coupled to the controlunit/processor 604 and commanded via the link to the remote facility607. This therefore provides for remote control of systems on the tank.

Referring now to FIGS. 29 and 30, another embodiment of a fluid levelmeasuring system in accordance with the invention for particular usewith storage tanks includes a buoyant housing 608 which floats on theliquid in the storage tank housing. Housing 608 includes a firsttransducer 610 arranged to face upward and a second transducer 611arranged to face downward.

Transducer 610 may be an ultrasonic or RF transducer which is capable ofproviding information to enable a determination of or possibly actuallydetermining the range of distance to the top of the storage tank, i.e.,the distance between the housing 608 and the top of the storage tank. Iftransducer 610 is an ultrasonic transducer, it directs ultrasonic wavesat the inner surface of the top wall of the storage tank and receivesreflected ultrasonic waves.

Transducer 611 may be an ultrasonic transducer which is capable ofproviding information to enable a determination of or possibly actuallydetermining the range or distance to the bottom of the storage tank. Iftransducer 611 is an ultrasonic transducer, it directs ultrasonic wavesat the inner surface of the bottom wall of the storage tank and receivesreflected ultrasonic waves.

A processor/communications unit 612 is connected to transducers 610, 611and, when the transducers 610, 611 only provide data about the reflectedwaves but not the range or distance information, the processordetermines the range or distance between the housing 608 and both thetop and bottom of the storage tank. From the range or distancedeterminations, processor 612 is thus capable of determining the level(L) of the liquid if the height (H) of the tank is known (and providedto the processor 612). The processor 612 could also correct for othervariables in the determinations, such as temperature, pressure and gasdensity as disclosed herein.

If the speed of sound in the liquid or the gas is provided to orotherwise determined by sensors connected to the processor 612, it canthen determine the fluid level using the data from only one of thetransducer 610, 611. For example, if the speed of sound in the liquid isknown, the processor 612 can determine the level of fluid based on thedata provided by transducer 611.

In one embodiment, a reference target is arranged in the field of viewof transducer 610 and thus, only transducer 610 would be needed toenable a determination of the level of liquid in the tank. In this case,housing 608 could not include transducer 611.

Processor 612 includes a communications unit or system whichcommunicates with the remote facility 607, either directly orindirectly, e.g., through an intermediate structure which receiveswireless signals from the processor/communications unit 612 indicativeof the level of liquid in the tank and relays them to the remotefacility 607.

It is noted that additional methods for measuring the level of liquid inthe storage tanks may be used in the invention, such as those describedin a book, Measurement and Control of Liquid Level. Any of these levelmeasuring techniques may be use din the invention, when used incombination with a communications unit which is capable of forwardingthe measured liquid level to a remote facility or engaging inbi-directional communications with a remote facility to enable theremote facility to initiate a liquid level measurement.

Telematics for Reservoirs

In a similar manner as the condition and fluid level in storage tanksare remotely monitored as described above, open reservoirs can also beremotely monitored. As shown in FIG. 38, a reservoir 200 generallydiffers from a storage tank in that it does not include a cover and istherefore exposed to the ambient atmosphere. Nevertheless, one or morewave receiving devices 202, or other fluid level measuring devices, caneach be positioned to have a field of view of the upper surface of thereservoir 200, and optionally a reference target in the reservoir if oneis used, and therefore enable a determination of the level of fluid inthe reservoir, of information about the chemical nature of the fluid,and the other information described above for monitoring storage tanks.Each fluid level measuring device 202 may have any of the configurationsdisclosed above, e.g., the ultrasonic variation or the opticalvariation.

Information about the chemical nature of the fluid and other informationabout the fluid and its properties, e.g., temperature, acidity,alkalinity, purity, composition, can also be determined by positioningone or more sensors 204 in contact with the fluid in the reservoir 200.

A processor or controller 206 is wired or wirelessly coupled to the wavereceiving devices 202 and fluid property sensor or sensors 204 and isprovided with the location of the reservoir 200. Since the location ofthe reservoir 200 is typically invariable, the location, once providedto the controller 206, does not need to be changed, as well as anassigned identification (ID) of the reservoir 200 for monitoringpurposes.

The remote facility which monitors the reservoirs 200 would receivemessages, e.g., via the Internet or a satellite link, or other means ofcommunication from the controller 206 and its associated communicationsunit, each containing the location, or ID, of the reservoir 200 andinformation about the fluid therein obtained from the fluid levelsensor(s) 202 and/or the fluid property sensors 204. The remote facilitycould also be designed to enable monitoring of the reservoir 200 via thewave receiving devices if a bi-directional communications device iscoupled to or part of the controller 206 located at or near thereservoir. Thus, the fluid level sensor(s) and/or fluid propertysensor(s) 204 could be directed to obtain information about the fluidfrom the remote facility, and then transmit the obtained information tothe remote facility.

A report about the reservoir 200 can be compiled by a processor orcontrol unit at the remote facility and alarms or warnings provided tomonitoring personnel if a problem is detected with any of the fluids inthe reservoirs or a problem is detected with any of the reservoirs.

When the communication unit in the controller 206 associated with thereservoir 200 allows for bi-directional communications, the reservoir200 can be provided with one or more controlled fluid adjustment systemsor components 208 which can be commanded by the remote facility toundertake a specific action. This would be in addition to the ability ofthe remote facility to command the wave receiving device(s) or otherfluid level measuring devices 202, and fluid property sensors 204 toundertake a reading. Such controlled fluid adjustment systems orcomponents 208 may be a cleaning system, a chemical introduction system,a valving system and the like. Any of these such systems can be coupledto the controller and commanded via the link to the remote facility.This therefore provides for remote control of systems associated withthe reservoir 200.

The fluid level sensor(s) 202 and/or fluid property sensor(s) 204 mayalso be associated with an initiation device which periodicallyinitiates them to obtain information about the fluid. A wakeup sensorsystem (not shown) may also be provided for detecting the occurrence ofan internal or external event, or the absence of an event for a timeperiod, requiring a change in the frequency of monitoring of thereservoir 200. The initiation device is coupled to the wakeup sensorsystem and change the rate at which it initiates the fluid levelsensor(s) 202 and/or fluid property sensor(s) 204 to obtain informationabout the fluid in response to the detected occurrence of an internal orexternal event by the wakeup sensor system. This type of system would besimilar to the cargo monitoring wake-up system described with referenceto FIG. 22.

In a similar manner as reservoirs are monitored in accordance with theinvention, lakes, ponds and any other contained body of water or fluidmay be monitored.

Gradients

In some applications of the ultrasonic, electromagnetic and opticalreceiving devices, in particular, use of such devices for determininginformation about a fluid in an enclosed storage tank, there may be gasdensity gradients caused by temperature variations and/or by variationsin the make-up or composition or chemical nature of the gas or liquid inthe storage tank. For example, in a liquid storage tank, a mixture ofgasses could separate with the more dense gas near the liquid surfaceand the less dense gas near the top of the storage tank. This gasdensity gradient may affect ultrasonic waves and therefore, in theembodiment described above wherein an ultrasonic sensor is arranged atthe top wall of the storage tank, the determination of the distancebetween the ultrasonic sensor and the upper surface of the liquid. Toensure reasonable accuracy of the determination of the distance betweenthe ultrasonic sensor and the upper surface of the liquid, and thus anaccurate assessment of the fluid level, any gas density gradient shouldbe compensated for.

One way to achieve this would be to determine the gas density atmultiple, spaced-apart locations in the tank, i.e., in the area in whichgas is present in the tank which would be the area between the uppersurface of the liquid and the top of the tank. If the gas densityreadings from appropriate gas density sensors are all equal, this wouldbe indicative of the lack of a gas density gradient. However, if the gasdensity readings are different, a processor which determines thedistance between the ultrasonic sensor and the upper surface of theliquid (and uses this distance determination to determine the level offluid in the storage tank) must compensate for the gas density gradientif it affects the ultrasonic waves.

The embodiment wherein the level of liquid in a storage tank isdetermined is thus especially appropriate environment for a technique tocompensate for gas density gradients or gaseous stratification.

In some cases, a combination of an optical system such as a camera andan ultrasonic system can be used. In this case, the optical system canbe used to acquire an image providing information as to the vertical andlateral dimensions of the scene and the ultrasound can be used toprovide longitudinal information, for example. In another case, anoptical system can be used to characterize the contents in a containeror storage tank and an ultrasonic system used to determine the distanceto the object or the fluid level.

Any of the transducers discussed herein such as an active pixel or othercamera can be arranged in various locations in the vehicle including ina headliner, roof, ceiling, rear view mirror assembly, an A-pillar, aB-pillar and a C-pillar or a side wall or even a door in the case of acargo container or truck trailer. For storage tanks, the roof isgenerally a good location for mounting ultrasonic-based level detectorsand a wall is a good location for mounting optical systems.Nevertheless, for an ultrasonic-based level detector, any location wherethe detector has a field of view oriented toward the upper surface ofthe fluid would be suitable. For an optical system, any location wherethe detector has a field of view of any part of the fluid would besuitable. In this case, care should be exercised to ensure that theoptical system has a view of the fluid even when it is at a low level.

Both bladder and strain gage weight sensors can also be used inmeasuring the mass of fluid in a storage tank or container. Use ofweight to measure the quantity of fuel in a vehicle fuel tank isdiscussed in U.S. Pat. No. 6,615,656 and U.S. Pat. No. 6,892,572, bothof which are incorporated by reference herein. Many of the techniquesdiscussed therein are also applicable to determining the quantity offluid in tanks and other containers.

As mentioned, optical systems can be effectively used to monitor thelevel of a fluid in storage tank. In one such implementation, a scalecan be projected from the imager and the point where the fluid coversthe image on the wall can be easily determined. Thus, in one smallpackage that does not require painting a scale on the tank wall, forexample, an accurate measurement of the level at the wall can bedetermined. Again, multiple such systems can be used to account for therotation of the tank or an angle measurement sensor can be incorporated.A preferred implementation is to use three imagers of a prism designedto display and record the reflection of a scale on three walls. Such adevice can be mounted in a single location such as 602 in FIGS. 25 and26 as a simple, low power device.

Frac tanks and reservoirs may also be monitored by, in addition tomotion and sound detectors, by RF detectors which may be mounted to thehousing of the Frac tanks or structure around the reservoir. RFdetectors would detect approaching people or vehicle when, for example,a person has or is using a cell phone or other RF transmitter.

Monitoring the Flow in Pipelines

The teachings of inventions disclosed herein can be applied to remotemonitoring of fluid flow in conduits such as pipes and tubes and in oilpipelines in particular. Several conventional methods are available forthe measurement of such fluid flows such as Doppler ultrasonic asillustrated in FIG. 31 and transit time ultrasonic as illustrated inFIG. 32. In each case, transceivers 622 mounted to the conduit bothtransmit and receive ultrasonic or sonic waves. For the purposes of thediscussion about fluid flow monitoring in conduits, ultrasonic willinclude those waves in the sonic frequency range. The ultrasonic Dopplertechnology generally requires that there be something suspended in thefluid that can reflect the ultrasound waves and thus in general wouldnot be applicable to the measurement of oil flow in pipelines. Althoughthe transit time example in FIG. 32 shows the transceivers 622 near eachother and on opposite sides of the conduit, an alternate approach is toplace them at some distance away and to time the transmission from onetransceiver to the other so that the time of flight can be determined ateach transceiver, as discussed below.

Another technique which is applicable when it is possible to install theapparatus while the pipe is under construction is a turbine flow meteras illustrated in FIG. 32. In a turbine flow meter, the rotation of arotor 623 is proportional to the flow of the fluid. Rotation of therotor 623 can be measured by many methods such as magnetically as shownin FIG. 33 using a magnetic pick-up device 624.

The measurement of a pressure drop across an orifice, not shown, isanother common method of determining flow, but can only be achieved atthe expense of introducing an energy loss in the fluid flow. Generally,this would not be permitted in oil pipelines for example. The use of aPitot tube which measures the stagnation pressure or the pressure tostop the fluid flow in a particular part of the flow can be an effectivetechnique and a variation of this approach is the target flow meterwhich measures the force on a target 625 placed in the flow as isillustrated in FIG. 34.

Other well-known flow measurement systems, which are applicable herein,include positive displace flowmeters, Coriolis mass flowmeters, thermalflowmeters, variable area flowmeters and others. Any of the flowmeasuring techniques discussed herein need to be compensated forenvironmental conditions and be accurately calibrated.

The apparatus for monitoring fluid flow in a pipe can be designed intothe pipe installation in order to ensure that there is no leakage andsuch systems are now in use. Generally, they are hard-wired or sendtheir information by telemetry back to a control station. A moredifficult problem is to determine whether fuel is being stolen bythieves tapping into a pipeline distant from the monitoring stations. Inorder to combat this theft, pipeline owners have attempted to installmonitoring stations at various points along the pipeline. However, whenthis happens, thieves frequently destroy the measurement systems sincetheir locations are obvious. What is needed, therefore, is a monitoringsystem that can be retrofitted to an existing pipeline and whosepresence cannot be easily discovered by potential thieves. Such a systemwill now be discussed.

Any of a variety of flow measuring systems can be used depending on theaccuracy required and the distance between monitoring locations. For thepurpose of this exemplary case, assume that the owner wants a monitoringstation every mile of pipeline so that when a theft is in progress theowner can determine the location within 1 mile of the theft site. Assumealso that the monitor must not be detectable by the thief as otherwisehe or she would destroy the monitor either where the theft is takingplace or a variety of locations in order to divert attention from thetheft site. The monitor must be able to communicate with the home ormonitoring station wirelessly, for example, by satellite, cell phone orthe internet if it is available. Since each monitoring unit will beisolated, it should be battery powered and in order to keep the batteryor capacitor (which stores energy and thus functions as a battery forthis example) small, there should be a recharging mechanism. Finally,the entire package should be capable of being inserted into an existingpipe through a hole drilled into the pipe and then plugged and repaintedor covered so that its presence is not easily detected.

Such a device and system is illustrated at 630 in FIGS. 35 and 36. InFIG. 35, two spaced apart sections of a conduit such as a pipe 640 areillustrated each containing a sensor assembly or sensing assembly 630.The sensing assemblies 630 are shown on opposite sides on the pipe 640as is conventional but in this implementation the separation of thesensor assemblies 630 will, in general, be much larger than the pipediameter and thus both can be placed on the top of the pipe, forexample, to facilitate transmission from the associated antennas.

A schematic of one implementation of the sensor assembly 630 isillustrated in FIG. 36. An energy generating system or energy harvestingsub-assembly includes a housing 636 and a rotatable element such as animpeller 632 mounted to the housing and which is caused to rotate byvirtue of the flow of the fluid indicated by vector 620. Rotation of theimpeller 632 in turns causes a rotor 633 to rotate within a coil 631generating a current therein. The coil 631 and rotor 633 are arranged inthe housing 636. The rotor 633 contains segments of alternatepolarization as is well known in the art. The current flows to a housingand electronic assembly 636 where it is used to recharge the battery orother energy storage system or element therein (not shown). Each sensorassembly 630 includes one or more flow measuring devices. For example,ultrasonic (or sonic) transceivers 634 may be provided and transmit andreceive ultrasonic signals to and from a similar transceiver at anotheradjacent location in the pipeline. Transceivers 634 may be directlycoupled to the rotor 633 to receive current therefrom and/or to theenergy storage system to receive stored energy therefrom.

The sensor assembly 630 can also contain a vibration transducer 635which is arranged in contact with the pipe wall itself and listens forvibrations that are traveling in the pipe material. The output from boththe ultrasonic transceiver 634 and the vibration transducer 635, alongwith information from any other resident sensors and diagnostic circuits(not shown), are fed after appropriate processing in a processing orcontrol unit (not shown but possibly situated in the housing 636) toantenna 637 for transmission to a satellite, the internet or othertelematics system. Although in this example is it contemplated that eachsensor assembly 630 will communicate directly to the telematics orcommunications system (which may be part of or associated with thecontrol unit), this need not be the case and a mesh, ad-hoc or othernetwork scheme can alternately be used.

There are alternative embodiments of the foregoing pipeline monitoringsystem which also provide for transmitting fluid flow information frommonitoring stations, e.g., sensor assemblies 630, along a length of thepipeline to one or more secure stations that can transmit the data to asatellite, the internet or otherwise to one or more facilities whichmonitor the pipeline for leakage or theft. One method is to modifyvibration transducer 635 so that in addition to listening to vibrations,it can also excite vibrations in the pipe 640. Such vibrations cancontain information as to the conditions such as fluid flow rate at thevibrating location and additionally relay information from other similarstations. Thus, the pipe vibrations become a method of communication ata speed of about 3.7 miles per second along the pipeline. A secondmethod is to transmit radio frequency or other electromagnetic wavescontaining similar information using an antenna in the fluid flow, notshown. These methods are schematically illustrated in FIGS. 37A and 37B.One key advantage of these methods is that they work well whether thepipeline is buried or above ground. In some cases, more than one systemcan be placed at a particular monitoring location to provide redundancy.

Each sensor assembly 630 can be inserted into a hole in the pipelinewhich has been drilled for that purpose. Generally, flow in the pipelinewill be stopped while this installation is accomplished but this may notneed to be the case provided a special device is created to drill thehole and insert the sensor assembly 630 under pressure while the flow isongoing. Since the antenna 637 of each sensor assembly 630 must have aclear view of the sky, and if the pipeline is buried under several feetof soil, it may be necessary to connect the assembly 630 to an antennaexternal to the pipe 640 but buried under a small amount of soil. This,of course is not a problem for above ground pipelines wherein theantenna 637 may be arranged on an outer surface of the pipe 640.

For the ultrasonic (or sonic) flow measurement, each transceiver 634would send an accurate measurement of the time that it sent and/orreceived an ultrasonic pulse which could be synchronized by variousmethods including a GPS receiver within each sensor assembly 630 thatwould time-stamp the messages sent or synchronize an accurate clockwithin the sensor assembly 630. Alternately, the minimum informationfrom one or more GPS satellites would be sent, such as the time ofarrival of a GPS signal and perhaps the number of cycles receivedthereafter, along with the sensor assembly transmission. Since theremote monitoring facility would know the location of the sensorassembly 630 and the position of the GPS satellite(s), it can easilydetermine the time associated with the transmission or reception of theultrasonic pulse at the transceiver 634 of the sensor assembly 630. Bythese methods, the remote station 641 can determine the time that eachsensor assembly 630 sent an ultrasonic pulse and when each adjacenttransceiver 634 received the pulse and thus it can determine the flowvelocity of the fluid in the pipe based on the time of travel differencebetween forward and reverse to the fluid flow transmissions. If it isdetected that the flow velocity decreased at a transceiver, then themonitoring station would know that, for example, a leak had developed orthat fluid was being diverted, stolen or leaking. If the transceiversare located at one mile intervals, then the remote station would know anapproximate location within one mile of where the theft or leak wasoccurring.

Each sensor assembly 630 is connected to a processing unit or controlunit which may reside in the housing 636 or at another locationproximate the sensor assembly 630, or on or proximate the pipe 640. Theprocessing or control unit monitors transmission and receptions ofultrasonic waves from and to the ultrasonic transceivers 634, in themanner described above, and derives information about a speed of flow ofthe fluid in the pipe 640. The telematics or communications unit mayreside in the control unit and be connected to the antenna 637 so thatthe derived information is converted into a signal by the telematics orcommunications unit for transmission by the antenna to the remotelocation 641. In a similar manner, any information derived by thecontrol unit from data provided by sensors or transducers is alsotransmitted to the remote location 641.

For a thief to tap into a pipeline, he or she would need to drill a holein the pipeline and attach a pipe or hose thereto. The drilling activitywould in general create vibrations in the pipe for a considerabledistance which could be sensed by vibration transducer 635. Thus, themonitoring station 641 should be able to determine that someone isattempting to tap into the pipeline before he or she succeeds. Toconclude, a remote pipeline monitoring facility using the exemplarytechniques described herein can monitor a pipeline to determine thatsomeone is attempting to steal product from the pipeline before he orshe succeeds and also to determine the location where this activity istaking place. Failing to prevent the initiation of the theft, themonitoring facility 641 can determine that product is being stolen andagain where it is occurring.

If the system is carefully calibrated at a time when it is known thatthere is no loss of product, then differential readings from time totime and from station to station would provide more accurate informationthan an absolute reading from a single location. Errors in the devicesthat existed when installed or that developed slowly over time can thusbe accounted for.

In any of the embodiments wherein electronic components are used, thecomponents may be designed for low power operations. Moreover, anytransmission frequencies can have a low bandwidth to further lengthenuse between battery changing or charging.

Remote water monitoring is also contemplated in the invention sincewater supplies are potentially subject to sabotage, e.g., by theplacement of harmful chemicals or biological agents in the water supply.In this case, sensors would be arranged in, on, within, in connectionwith or proximate water reservoirs, tanks or pipelines and powered inthe manner discussed above, and coupled to a communication system asdiscussed above. Information provided by the sensors is periodicallycommunicated to a remote site at which it is monitored. If a sensordetects the presence of a harmful chemical or agent, appropriate actioncan be taken to stop the flow of water from the reservoir to municipalsystems.

Even the pollution of the ocean and other large bodies of waterespecially in the vicinity of a shore can now be monitored for oilspills and other occurrences.

Similarly, remote air monitoring is contemplated within the scope of theinvention. Sensors are arranged at sites to monitor the air and detect,for example, the presence of radioactivity and bacteria. The sensors cansend the information to a communication system which transmits theinformation to a remote site for monitoring. Detection of aberrations inthe information from the sensors can lead to initiation of anappropriate response, e.g., evacuation in the event of radioactivitydetection. In a special implementation, probe automobiles or othervehicles can be used to monitor the air on highways for spills,pollution etc.

The monitoring of forests for fires is also a possibility with thepresent invention, although satellite imaging systems are the preferredapproach.

An additional application is the monitoring of borders such as the onbetween the United States and Mexico. Sensors can be placed periodicallyalong such a border at least partially in the ground that are sensitiveto vibrations, infrared radiation, sound or other disturbances. Suchsensor systems can also contain a pattern recognition system that istrained to recognize characteristic signals indicating the passing of aperson or vehicle. When such a disturbance occurs, the system can“wake-up” and receive and analyze the signal and if it is recognized, atransmission to a communication system can occur. Since the transmissionwould also contain either a location or an identification number of thedevice, the authorities would know where the border infraction wasoccurring.

Above, the discussion of the invention has included the use of alocation determining signal such as from a GPS or other locationdetermining system such as the use of time of arrival calculations fromreceptions from a plurality of cell phone antennas. If the device islocated in a fixed place where it is unlikely to move, then the locationof that place need only be determined once when the sensor system is putin place. The identification number of the device can then be associatedwith the device location in a database, for example. Thereafter, justthe transmission of the device ID can be used to positively identify thedevice as well as its location. Even for movable cargo containers, forexample, if the container has not moved since the last transmission,there is no need to expend energy receiving and processing the GPS orother location determining signals. If the device merely responds withits identification number, the receiving facility knows its location.The GPS processing circuitry can be reactivated if sensors on the assetdetermine that the asset has moved.

Once the satellite or other communication system has received a messagefrom the sensor system of at least one of the inventions disclosedherein, it can either store the information into a database or, morecommonly, it can retransmit or make available the data usually on theInternet where subscribers can retrieve the data and use it for theirown purposes. Since such sensor systems are novel to at least one of theinventions disclosed herein, the transmission of the data via theInternet and the business model of providing such data to subscribingcustomers either on an as-needed bases or on a push basis where thecustomer receives an alert is also novel. Thus, for example, a customermay receive an urgent automatically-generated e-mail message or even apop-up message on a particular screen that there is a problem with aparticular asset that needs immediate attention. The customer can be asubscriber, a law enforcement facility, or an emergency servicesfacility, among others.

An additional dimension exists with the use of the Skybitz or ubiquitousinternet system, for example, where the asset mounted device has furtherwireless communications with other devices in, on or near the asset.Tagged items within or on the assets can be verified if a local areanetwork exists between the off asset communication device and otherobjects. Perhaps it is desired to check that a particular piece of testequipment is located within an asset. Further perhaps it is desired todetermine that the piece of equipment is operating or operating withincertain parameter ranges, or has a particular temperature etc. Perhapsit is desired to determine whether a particular set of keys are in a keybox wherein the keys are fitted with an RFID tag and the box with areader and method of communicating with the off asset communicationsdevice. The possibilities are endless for determining the presence oroperating parameters of a component or occupying item of a remote assetand to periodically communicate this information to an internet site,for example, either directly or by using a low power asset monitoringsystem such as the Skybitz system.

The Skybitz or similar system can be used with cell phones to provide alocation determination in satisfaction to US Federal regulations. Theadvantage of this use of Skybitz is that it is available world wide anddoes not require special equipment at the cell phone station. This alsopermits an owner of a cell phone to determine its whereabouts for caseswhere it was lost or stolen. A similar system can be added to PDAs orother CD players, radios, or any other electronic device that a humanmay carry. Even non electronic devices such as car keys could beoutfitted with a Skybitz type device. It is unlikely that such a devicewould have a 10 year life but many of them have batteries that areperiodically charged and the others could have a very low duty cyclesuch that they last up to one year without replacement of the batteryand then inform the owner that the battery is low. This informationprocess could even involve the sending of an email message to theowner's email stating the location of the device and the fact that thebattery needs replacement. A ubiquitous internet system can be used inplace of the SkyBitz system when it becomes available.

Although several preferred embodiments are illustrated and describedabove, there are possible combinations using other geometries, sensors,materials and different dimensions for the components that perform thesame functions. At least one of the inventions disclosed herein is notlimited to the above embodiments and should be determined by thefollowing claims. There are also numerous additional applications inaddition to those described above. Many changes, modifications,variations and other uses and applications of the subject inventionwill, however, become apparent to those skilled in the art afterconsidering this specification and the accompanying drawings whichdisclose the preferred embodiments thereof. All such changes,modifications, variations and other uses and applications which do notdepart from the spirit and scope of the invention are deemed to becovered by the invention which is limited only by the following claims.

1. An arrangement for monitoring a structure at a fixed location,comprising: a sensor system arranged to obtain information about thestructure or an interior of the structure different than the location ofthe structure; and a communication system coupled to said sensor systemand being provided with a location of the structure, said communicationsystem being arranged to transmit the information about the structureobtained by said sensor system and the location of the structure to aremote facility.
 2. The arrangement of claim 1, wherein said sensorsystem includes at least one of an electromagnetic sensor, camera,ultrasound sensor, capacitive sensor, chemical sensor, moisture sensor,radiation sensor, biological sensor, temperature sensor, pressure sensorand radiation sensor.
 3. The arrangement of claim 1, wherein said sensorsystem includes at least one of an intruder sensor, a fire detector, asmoke detector, a water detector and a pollution sensor.
 4. Thearrangement of claim 1, wherein said sensor system is arranged toperiodically obtain information about the structure and provide theinformation to said communications systems which transmits theinformation to the remote facility.
 5. The arrangement of claim 1,further comprising a power source independent of a power grid extendingoutside of the fixed structure for providing power to said sensor systemand said communications unit.
 6. The arrangement of claim 1, whereinsaid sensor system further comprises an initiation device forperiodically initiating said sensor system to obtain information aboutthe fixed structure, further comprising a wakeup sensor system fordetecting the occurrence of an internal or external event, or theabsence of an event for a time period, requiring a change in thefrequency of monitoring of the fixed structure, said initiation devicebeing coupled to said wakeup sensor system and being arranged to changethe rate at which it initiates said sensor system to obtain informationabout the fixed structure in response to the detected occurrence of aninternal or external event by said wakeup sensor system.
 7. Thearrangement of claim 1, wherein said sensor system is controllable bythe remote facility to obtain information about the fixed structure. 8.The arrangement of claim 1, wherein the fixed structure is a house, boator airplane.
 9. The arrangement of claim 1, wherein said sensor systemincludes an integral energy providing system and is wirelessly connectedto said processor.
 9. A method for monitoring a fixed structure,comprising: arranging a sensor system to obtain information about thefixed structure different than the location of the body of fluid;obtaining information about the fixed structure via the sensor system;and transmitting the obtained information about the fixed structure andthe location of the fixed structure to a remote facility.
 10. The methodof claim 9, further comprising wirelessly coupling the communicationsystem to the sensor system.
 11. The method of claim 9, furthercomprising: monitoring an environment around the fixed structure toobtain information about the environment around the fixed structure; andtransmitting the information about the environment around the fixedstructure to the remote facility along with the information about thefixed structure and the location of the fixed structure.
 12. The methodof claim 9, further comprising periodically initiating the sensor systemto obtain information about the fixed structure.
 13. The method of claim9, further comprising: detecting the occurrence of an internal orexternal event, or the absence of an event for a time period, requiringa change in the frequency of monitoring of the fixed structure; changingthe rate at which the sensor system obtains information about the fixedstructure in response to the detected occurrence of an internal orexternal event.
 14. The method of claim 9, further comprising: arrangingat least one reactive system to adjust a condition in the fixedstructure; and controlling the at least one reactive system by theremote facility based on the transmitted information about the fixedstructure obtained by the sensor system.
 15. The method of claim 9,further comprising controlling the sensor system via the remote facilityto obtain information about the fixed structure.